IPhone 4S or 5? Also, cheapest iPhone plan with unlimited data and texting?

We're planning to get our daughter an iPhone 4S or 5. My daughter doesn't talk much but would use it for apps, texting, making videos, taking photos, etc.

I foresee us getting another phone for her in 2+ years. I'm thinking the 4S would be fine but what significant improvements might make the 5 better? Or do some people prefer the 4S to the 5 (and why, if so)? The price difference between a 16gb 4S ($360) and 16gb 5 ($405) is small but there's no point if people prefer the 4S to the 5. We won't spend the $550 for the 5S.

As for plans, the Virgin Mobile plan seems like our best bet at $30 a month for unlimited texting and data (even though the data is slower after a certain point) and 300 minutes for calls. There may be better plans out there price-wise but I'm not aware of it. A negative of the plan is that VM phones are difficult, if not impossible, to unlock so using them outside the US Is impossible. But we could use my daughter's current unlocked Pantech (AT&T) GSM phone if we were to go outside the US

Thanks for helping us sort through the confusion.

TBH, iPhones are money down the drain. They sell for an average 2x higher than any android phone yet Android phones are commonly better and more cost efficient. Buying I phones are some of the worst decisions I've made sending all that money down the drain.

I heavily encourage you to think about buying other phones, as many phones can do much more than the iPhone while costing a lot less.

Some thing about Android:
Android dominates 81% of the smartphone market share.
Google Play has a higher market share and 25% more downloads than iTunes.

The latest google phone, Nexus 5, has twice the battery and processing power of the iPhone 5S while COSTING LESS!

Final Note: If you have decided to make the wrong decision, get an 4S because there's almost no difference between all the iPhones. Apple just likes to over hype one little feature every release.