Since the M80s are 4 ohm speakers, I'd look into getting separates. Some receivers will drive 4 ohm loads, but if you're looking at an entire Axiom HT setup, I'd highly recommend buying at least a three channel amp to run the front end (R/C/L), as you're looking at 4 ohm load for the mains and 6 ohm loads for the rest of the speakers (if you're going to best match the M80s). If you're going to fork over the cash for a receiver that will handle this well, I don't think it's much a jump to move right into separates.
If you're on a budget, I'd look at Outlaw Audio's combos. They'll discount preamp/amp combinations. While this will cost more than most midline receivers, I think you'll be happier with it in the long run. Also check out Rotel (though the bang/buck ratio isn't what it used to be), Arcam, and Anthem (more expensive, but these can be found on e-bay from time to time at a discount). If memory serves, Marantz used to have a high bang/buck ratio, but I'm not sure where they stand today.
Happy hunting!
