These are great in the lakes...
http://www.gibbsfishing.com/products_herringdodger.asp
Take the hooks off these, add a back swivel...
http://www.gibbsfishing.com/products_clendonstewart.asp
http://www.gibbsfishing.com/products_wonderspoon.asp
I like these best, Clendon spoons, hook off add swivel.. leader hook/lure about 3' - 4' back Hootchies/worms/leeches/flies about 2'-3', 12#-15# flourocarbon leader (stiff) to get active.
http://www.gibbsfishing.com/products_trollingstewart.asp
Light lines?.. Sharp hooks!
RS, I think 200', even with 20# braids would strain most fly reel drags even with squirts & small spoons. The dodgers even small create a lot of action/drag, but that's held by a DR clip.
The key to all these attractors is to not troll too fast or they spin. They're designed to wobble. If they spin, they may start to helicopter in a bigger circle and get erratic. Use flashers or spinners for higher speed.
Luhr Jensen smaller dodgers, about 4"-5" seem to go on sale every winter at Cdn Tire. colours tend on the wild side. Check their L-J discount bin. They always have some flutter spoons in there that might work, but I haven't tried them. Both Cabela & BPS put their residual stock of flashers on sale about this time through Christmas. The residual stock are colours left over and usually pretty small sizes. Flashers for faster spinning presentations and dodgers for slower wobble-presentations.
You could also try trolling rattle-wiggle warts and shallow Rapalas. It works on trout & bass down deep 4'-6' behind a spoon. The Rapala would probably mimic needlefish. Ghost & black-white work best for me (lakes) at depth or low light.
Also, you could try small-blade gang-trolls down that deep at faster speeds. Due to the light conditions, I'd probably paint the blades white, glow or red/black with a white stripe.
The downrigger clip would hold the drag from the lure and eliminate mainline twist, but the depth of line you have down brings us back to the start of the thread.
Other than buying a new reel, I tend to believe 30# (0.009"-0.010") powerpro cuts that drag to 25%-40% of 20# mono. When I drag small Worden Sea Tigers (big deep-dive plugs), using 40# Stren braid, the plugs run about their stated depth, 35', and the line's about 45degrees from the boat, the plug's about 70 degrees from the entry point of the line with 150' of line out at around 2-3 knots. (You can watch that near verticle dive when they're right by the boat with 30' line out. Using 25# BigGame, they dive half or less as deep with the same amount of line out. It's hard to tell because the 30' of line carries the plug so far back... Less line drag with braid.)
Anyway, try stripping the hooks from a good spoon to make small flashers and add a back swivel to tie your hootchies/leader.
Cheers