need to pick an embedded system

Hi, this isn't strictly speaking a programming question but I'm having difficulty getting a handle on it, so I thought I'd see if anyone had any comments.

Basically I'm developing some software that is going to eventually be run on an embedded device, and we need to develop a prototype. It's unclear so far what devices we'll need to develop for, but incorporating it into a smartphone is being tossed around a lot.

I've been asked to find an embedded system to do the prototype on, but I'm very much not a hardware guy and I'm having difficulty.

The software itself does fingerprint analysis and processing, would probably need around 3MB of RAM plus whatever overhead the compiler for the system added. Being able to connect to a simulated server would be important, so a USB or network connection would be needed. Of course, I'd also need any development tools necessary to develop for the system.

Some sort of rapid prototyping system would probably be ideal. Does anyone have any suggestions?