. More power, similar or less weight, proven platform and cheaper to go that route. The Mercury 450R's are from their racing line and meant for go-fast type boats rather than pushing big heavy boats and probably not the best option; again for the cost, you could probably get triple 300's for less. Just to mess with your head, have you thought about diesel inboards? I was on a new 36' Eaglecraft last summer with new Volvo D4's and DPS outdrives and it was pretty slick, especially with all that room at the back. It definitely made me reconsider what power I'd put on my boat if I was in your shoes. 
Thanks for the ideas and yes, definitely PM me your build list. I will inquire about the triple 300 Suzuki option. Great idea on the mounts. As far as the Optimus joystick system versus thrusters, I have done quite a bit of research on them and will go with the joystick. I like the virtual anchor feature that the Optimus gives you and the technology has come a long way.If you are happy with Suzuki, I'd probably stick with them. Twin DF350's "should" get the job done, but from the 33'+ boats I've either been on or seen the performance specs of, I think triple 300's is a better option. And not just for speed, you should see better mpg with three engines working easy vs two hard.
Instead of twin Yamaha 425's, I'd definitely go triple F300's - or even better, Merc 300's
As someone else said above, I'd install a bow thruster and forgo the joystick. Have you even seen a boat docking with a joystick? It is a loud and violent process with the engines shifting in and out of gear and revving up and down. The whole marina comes out to watch the show! That said, I have heard that the DF350's work better with joysticks than other outboards due to the dual props.
Definitely go with the Burnewiin mounts. I put mine on my boat six years ago (dealt directly with company as there were no dealers, they were great BTW) and they've been one of the best upgrades. This past winter I added a mount for a HD trap hauler. My buddy installed a few of the mounts in the hold of his boat so when he takes his downriggers, bbq, etc. off he can have them secured down below deck, something to think about.
For fuel capacity, I'd go with enough that you can have ~12 hrs running at cruising speed PLUS 20 - 25% reserve.
One of my wife and I's favorite conversations is planning our dream boat for when we retire and what we'd put on it. We're a few years away yet, but have been on most of the 30'+ aluminum boats to see what we like / don't like (haven't been on a Liquid Metal though). I've started keeping a "build list" of things we like and can PM it to you if you want. Appreciate that everyone's custom build is going to be different to fit their planned use case, so it may not be of interest to you.
www.boatblurb.com
www.boatblurb.com
Yeah, the electronics are going to be set into the dash, not on the dash. Already discussed with them and they will fit. I will post the info around the electronics later, after I have done some more research.
I am making the deck box a lot smaller than the one shown for that reason. I will also have an in floor fish box. I looked at a 33 Walker that had the davit and crane but I really don't plan on doing a lot of cruising with the boat and the wife likes being tied to the dock.
I wasn't going to add a kicker. I had debated that on my present boat but I like trolling on one large outboard. My 200 Suzuki is quieter than a kicker, I love the push up/down precise throttle control that increases/decreases throttle by 50 rpm increments, and I don't need a second set of controls. More hours but these new outboards really last.
Big boats don't need kickers. I have a 30HP on the commander and it's pretty much useless. I wouldn't run one if I had new outboards.
At a certain point a beam wind will overpower trying to control the bow from the stern as it is totally inefficient, as vessel size increases as does sail area and eventually the joystick won't work. The ROT developed by a bowthruster will significantly out maneuver any joystick system. Neat gadget though, good luck.
Thanks for your input. I am definitely rethinking the deck box. Love your boat. Looks like a total beast. Good idea on the davit plate.
I have twin 300hp Verados which are great for everything.....except backtrolling for halibut, just too much power. I don't know if the virtual anchor would be any better in a swell with a cross chop as a vessel has a natural tendency to seek the wind by the stern. I'd be interested to see if it could without driving you nuts (and your lines)
I can tell you one thing, the kicker is even worse in reverse. Which sucks because back trolling is why I wanted it.
Too much power? How do you back-troll? I always keep stern into wind, both engines on and in neutral 90% of the time, then kick one of them in reverse to get the lines straightish. Which motor i shift depends on whith way the boat needs to turn(which side is going under the boat), but they are only in reverse 10% of the time. Problem I see with virtual anchors is that often backtrolling is not to keep yourself geostationary, trying to do that messes with line angles, its to keep your drift in tune with subsurface currents.
Yes that's exactly what I do is trim up as much as possible. Unfortunately the original kicker was offset so I just left it that way to avoid repairs from changing the bracket. In hindsight I should have centered it. The other issue with the 30 is it has a severe rev limiter so it only ever gets up half throttle at best. I hate it so much. I also use my kicker to stay over my prawn gear and it really can't even keep up with that. If I'm in wind against current conditions I'm having to run back and forth 20 feet to the main controls and that's impossible to do solo.
Everyone has a preference.
