Well I was trying to make a hd for my xbox cause I have the retail 10gb and is not enough
know what you mean. i run a 160gb HDD in my main XBOX and i am down to my last 20gb.
I don't know where you are based but here in the UK i managed to get a free PC off a recycle scheme (its called Freecycle). Before it gave up the ghost i was able to rebuild my 160gb HDD with the original xboxhdm CD.
Alternatively you could get a mod-chip for the XBOX, install it & rebuild through Slayers Evox or AID 4.5. Or get a loan of a modern(ish) PC somewhere - anything to get you access to IDE ports & bootable USB. Just make sure you keep that eeprom safe somewhere as its importance cannot be understated.
Anyway good luck with what you do.