this is rudsters brother and i am very experienced in the xbox modding subject, i have many xboxs and some that work and some that dont, what kind of modding do you want to do, hard mod or soft mod, i could do it for you or anything you want just ask, im willing to trade my xbox for your harddrive,
EDIT: i have one you could put a bigger hard drive in with a hard mod only and another which is working and you could soft mod MAYBE
also the one you can hard mod is just missing the hard drive which is xbox specific