I just listed one of my accelerators on EBay. It's the Warp Engine 040, at 40Mhz. Has 64 Meg on it (expandable to 128 Meg, which can be had on EBay for about $10) and has fast-SCSI2 on-board.
This board was pulled from an Amiga 3000 Tower, though it will work in both the A4000 series systems. I do not think it will work in a desktop A3000, due to the clearance needed for the RAM.
The listing is here:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=220515135663
