Prindle 18 is cheap and simple, and buoyant enough for the two of you. The rudder system can be a pain (and arguably a poor design) but if you understand how to unload the springs while you use it, the blades go up and down quite easily. The rest of the boat is as simple as it gets.

325lb is a great weight -- any 16+ foot boat should work fine to start. IMO find whatever is the best quality of the boats available to you, and get it. You can always part with it after a year or two once you know what you're looking for in a cat.