Hmm, your dillemma is a unique one.
If you have the ability and do not really care what happens to your PC,(yeah right) back up your entire system, try whatever you think is necessary to install the Mac OS X, and if it doesnt work, then you'll always have your backups. While your at it, a clean install of Windows would help.
Sorry I can't be of more help.
EDIT: Oh, btw. There are places to get good used iMac and other Macs for the use of OS X. An new eMac might run you a good $1000. A used iMac like mine could go for $500 or even less.