Are deep V wheels only for fixed gear bikes?
Deep-sectioned rims -- particularly Velocity Deep Vs -- became popular among fixed gear riders because they came in a variety of colors (bling) and the larger section made that bling all the more prominent.

However, deep-sectioned rims have many applications beyond urban fixed gear bikes. They're typically heavier and don't do well in cross winds, but in straight-ahead road riding, they are thought to be more aerodynamic.

As long as the rims come with machined sidewalls, they'll work fine for your purposes. The machining greatly improves braking by making the contact point for the brake pads more consistent.

All that said, if you're riding around town or even doing more recreational road riding, I think you'll be better served by a smaller sectioned rim like the Velocity Aerohead.