Take a look at the Gallien-Krueger Backline 112. At 100 Watts, it has more power than you had inmind, but it gives you consistent sound at any volume, so you don't have to crank it up to get the sound you want. And it has lots of provision for patching in external effects, plus some unusual features like the heavy steel grill in front of the speaker (bulletproof!), and the cabinet that allows you tilt it back without the need for something to prop it up. I have this model's predecessor, the Backline 100, so I'm pretty sure you'll like the Backline 112.