Straight Talk vs. Verzion vs. Boost Mobile

My husband and I are looking to move out in the near future. We currently  do NOT pay rent, and we’re looking to cut costs where ever we can. We both currently have smartphones with Verzion Wireless. He has the iPhone 4S & I have the Droid Charge. I was not a happy camper when he said we might have to drop Verzion because I’m SO close to getting an upgrade to an iPhone! I hate android now. And I think it’s kinda not fair that he changes phones so much and I get stuck with his hand-me-down phones, so I kinda feel like I deserve the upgrade. But alas the phone bill will probably be too much when we move out on our own. I won’t have a job, I’ll be home with our daughter 24/7. And before you go ranting on how I need to get a job just think if you were an employer would you hire someone who has unpredictable seizures? Didn’t think so.

So my question is how good is Straight Talk & Boost Mobile? I know you can have smartphones with those too. Can you keep your same phone number?