I have heard of Aros, but I thought that was a linux distro with a UAE emulator to mimic the real AmigaOS; if it run on 68K I would love to try it 
auweia! seems to be a frequent misconception. aros68k not only runs on 68k, it runs many genuine amiga programs, and the goal is to run almost all of them. alas its still in experimental stage and can be pita depending on your hardware setting, dont let you disencourage if it doesnt fulfill your expectations at this time, its being worked on.
BTW I am not stuck on 68K and refuse to look somewhere else
I just prefer to remember it in that way, because for me, at that time, 3.0 was the best that you can ever run on a computer 
personally when it comes to amiga im almost stuck with it. im not even much into aros x86, given up on os4 and never got to actually try morphos, but this is everyones personal thing i guess.
Where I can get the source for the 68K aros? and how do you build for Amiga? My only Amiga experience was on argasm many decades ago, and a bit of Lattice C
Never did cross platform development, since the only computer for me was the Miggy 
more precisely, here you can find the sources and precompiled nightles (look for m68k stuff):
http://aros.sourceforge.net/nightly.phpand here you have a complete distribution with many goodies, but beware, its huge:
http://www.natami-news.de/html/distribution_download.html