not sure about other axles, but a good (and i mean GOOD) atlas could set you back 3-4k on its own, before you've modded the car to suit with link bars etc etc

strong as fuck though. seen people put down a reasonable amount more power than you with no issues with a decent atlas on the rear end.
other options would be include the 4ha (heavy but bomb proof) and i guess jag or US ford items...