Lots of great recommendations here. For coho on a single hander or switch I'm using Orivs Battenkill Large Arbors, Galvan Torques and Vosseler reels and think they are all great for the job and have stopped some large coho in their tracks. Consider Allen Fly Fishing's Alpha series, won't break the bank and for the price of one of the earlier mentioned reels you can get two Alphas, backing and lines. The only thing better than a nice reel is two or more nice reels.