Looking for an equivalent to a nice MBP i have, but that i can use for linux

i have a nice MBP 9,1, quad-core hyper threaded i7 @2.3 with 8 gigs of memory. as much as i like it, im looking for something equivalent, or better on the PC side that i can use for linux testing. the 1, i guess set, of requirements i have is that the CPU and GPU are both AMD, so i dont have to fuss with proprietary drivers. right now im looking at a few dell models, but im wondering if there are other makes/ models i should consider. trying to not go above $400-500