I own an Evo while a coworker has the Incredible. You know, battery life is going to depend a lot more on your individual usage. For example, I told this guy I had my phone rooted and configured so that I can get 2 full days without charging under moderate use. His jaw dropped. He never gets more than a day.
But then we talked about our usage, and we found out that I get about 50 emails a day via exchange. He gets about 300. I'm on voice calls about 2 hours a day. He's talking about 3-4 hours. He was unrooted.
So I had him root, configure it as ideally as possible. Battery life improved for him but still not better than mine. It's not really saying which phone has better battery life; I'm sure if I owned the Incredible, I could get it to go 2 days before a charge.
Personally, I like the size of my Evo. It's a much larger phone than the Incredible, so that's something to consider. Stock Evo battery is 1500mAh. Stock Incredible battery is 1300mAh. Smaller screen means less consumption, therefore smaller capacity battery.
Not sure what Verizon's plans look like, but I like Sprint's. The base plan is a net $80/mo. You get unlimited data, unlimited SMS, and free mobile-to-mobile minutes (no minutes used when calling a cell number, or when a cell calls you). Been with Sprint since 1999. Great coverage, dropped calls are very rare.