www.etherboot.org, this web site will make you the rom image, then you need the chip, mine was a 27c16 I think, then a programmer to burn the prom chip. The web site supports most any network card that has a spot for a 28 pin chip, etc.
Using this saite I've created a boot ROM image for CD boot. This way I need no hard disk and it's possible to use many cheapest network cards without boot PROM support. If you can't boot from CD-ROM you can try a floppy boot image ...
Greetings, Bernd