Where on the lake will you be staying? This time of year, the small mouth bass fishing really takes off. 30' of water with crayfish. You will also find some nice perch that way. For trolling with a down rigger, you can use various flutter spoons or smaller NKs. I havent trolled Keuka in a number of years, I focus on bass and jigging for lakers. A fun way to troll for bass is with woodchucks. They are a topwater fly that can be hard to find but if you have some, trolling points in ~ 30' of water will pull some large bass. Flat line them quite a distance behind the boat. The smallies will come off the bottom and smack them. If there are any floating weeds, its hard to keep the lines clean. Not a lot of action that way but the bass will be big.