Actually the option AMIX will disappear in the later version of the ROM's.
You're hardware is not supported, at least not out of the box, but you could at least try. Get the gateway unix driver CD if you intend to use any but original C= hardware.
Your A2090 might work, but I've only had experience with installing on an A2091. The 8Up! board is unknown.
More info on getting it working can be found at
http://www.amigaunix.com
