With the Seastar/Baystar kits matched to your motor type you don't have to worry about the ram having the right throw length to match the turning radius of the outboard, you also don't have to worry about the helm fluid capacity and how many turns of the wheel it is going to take you to go from hard port to hard starboard so I'm thinking for the cost of the kit... buy the kit.
The sea star kit is working fine on our boat but I would have to say that I may not bother spending the money on the new boat to convert. On smaller boats even though the motor is not turning once you install hydrualics when you stand to one side to work a downrigger, if you have a deeper V hull you cant the boat to one side and the keel acts like a rudder and turns the boat (like how you turn a kayak by leaning the keel over) So bottom line you don't end up getting as straight of a line as I had hoped for in anything under 22' with a V hull...
Make absoluely sure not to use plumbers tape when you install the hyraulic lines to the helm and ram, use liquid pipe dope. The dealer who installed mine used tape and I was forever having to flush the helm and filter my h-fluid after the tape broke down into peices in the system and started clogging the valves :-( Same old story if you want anything done right, do it yourself!!!