I have run the 205 Tiller with a Yamaha 115, Mercury Verado 200 and currently with a Etec G2 150.
The yamaha was a fine motor for that hull. Great hole shot and top end was around 34 mph. Great on gas. Trolled amazing.
The Mercury was a beast. 50 mph WOT. Was a pig on fuel. Didnt troll great without assistance of a drift sock
The etec has been my favorite so far. The power steering is amazing. 43 mph top speed. Trolls great and is as fuel efficient as the yamaha.
If you look back at some of my previous posts I think there will be some good info for you. Cheers