GPRS hardware recommendations

Hi all- I'm trying to get a GPRS network set up to serve a few old phones I have, but I don't really need anything beyond that. There's a daunting array of choices and scant documentation out there, so I just thought I'd ask, does anyone have any recommendations for what the least expensive hardware solution to implement GPRS would be? In particular though, I'd like to go with commercial non-SDR hardware, and I'd rather spend a tiny bit more if it would get something smaller... Are there any good GPRS-capable femtocells that work well with the Osmo stack? I'm looking at some old Ericsson gear but hoping for something more compact. Thanks in advance! -Ben