I found some links that may help us on building this project...
The first one is an actual machine that already build on an old console with linux, this is something we should be able to acheive..
a link about license about MAME
This one is a bit too fancy to build, but.. have a look, maybe it can give us an idea or build some thing cool like this one..
I'll keep u updated when i see some thing cool.. ^^ cheers