More choices with Alltel?

[ballyhoo]

I've read through the forum and haven't quite found what I'm looking for. I'm one of, probably only a handful, of people that are stuck with Alltel after Verizon bought the company. Alltel only has one option for Android and that is the Hero. I did manage to root it and flash a great ROM and overclocked to 710mHz but it leaves me wanting more. I'm wondering if its possible to use some other Sprint/Cellular South/etc. devices on the Alltel network. If so can someone point to a guide of some sort that may help me on my quest for a better Android device without having to buy out of my contract and switch to another carrier.
Thanks in advance,

CS