Good idea on mainboard - I do have an old ASUS P4 board here I can hack up. I'll check that out today. Right now I have to go into town for something, so it'll be a few hours.
If you don't find anything suitable on that mainboard and think I can be of assistance again, let me know:
http://www.maritex.com.pl/pl/shop/products/ggid/15955