a note on using aros on real hardware:
060 should be fine. easy way to setup aros on your amiga is to attach an amiga drive via usb to pc, download aros68k and contributions to a direstory set up as drive under uae, under uae to mount both the directory and the usb drive, copy the contents of dir to drive via uae and attach the drive to your amiga (all controllers should be fine, if not report back). its easy, i use to do that every other day or even more frequently.
what concerns performance: binaries will run with usual speed as under aos, confirmed 1:1 by benchmarks. where aros is slow its particularly some interface operations like gfx output (wanderer, zune, the graphics libs (intuition, layers and co may need optimizations that they miss since they ran before only on fast systems)). loading executables, partly disk operations are slower than they should be as well. some other areas, where apparent bugs play role. needs investigating and comparison with aros. memory allocation has been greatly improved lately, still 4 times slower than aos. hope this help.