Skookum makes a nice product from what I understand and think you would be happy with their product. In the cataraft category I'd also recommend taking a look at Dave Scadden's products (davescaddenpontooncraft.com) which I also understand are top quality.
Since you are going to split your time 50:50 lakes/rivers here are some "drier" options you might consider: Endure Boats 10' Aluminum Pram (endureboats.com), Hyde 11' Drifter (hydeoutdoors.com), Koffler Boats Inc. 10' Whitewater Pram (kofflerboats.com). Lavro offers an 11' Fly Fishing Boat (lavroboats.com) that might also be of interest. These boats all afford stable platforms from which to stand and fish, are dry, all appear to have sterns you could mount an electric motor/small outboard if you desire, and can all handle the white water you describe. Might be worth a look.