Can I ask what the kickstart replacement is for? Seems to mee AROS just needs to boot off standard pc equipment, there's no place to put a kickstart rom in a PC and even if there was it's a bad idea to put system code in hardware, it's just a big dongle in the old (classic) Amigas.
For using AROS on x86 Hardware, you dont need a Kickstart. But AROS is intended to be binary compatible with real Amiga OS when ported to a 68k Amiga. For that, you would need a Kickstart. It is also very interesting for UAE, WinUAE and Amiga Clones like the minimig.