I hate to be the bearer of bad news, and obviously not being there, you can't take my word for it... A motherboard I was screwing with 2 weeks ago, BIOS booted fine. Started Win98 setup from CD rom fine, boots off of 3.5 fine... but dies the second restart, tried 4 different Win98 disks, 2 95 disks, an NT disk, but it loads up the PNP drivers, reboots, and locks, it'll go into safe mode though,, it's a weird one, the slightest short can cause that. Advice, go to Radio Shack or somewhere and BUY A STATIC WRIST STRAP, it's not perfect, and it needs to be clipped to bare metal (and the case always plugged in for constant ground) but hopefully this will never happen to you again. you may want to find someone with an old SCSI drive and SCSI adapter, and try that... just to see if it'll go...Do you have any old school ISA IDE controllers? you may want to try that too. may be a short in the controller chip onboard....
Good Luck...
and Find a friend with lots of old spare parts, probably a small mom n pop computer store nearby... They might hook up the IDE card and/or SCSI stuff for free if they can't use it...