Another option is maybe just making a gender bended version of Vega I suppose. Those seem to be pretty popular right now, you could just design a tube top like shirt to match his pants and just wear that. I think that may be your best bet. If you're going to make a body suit defiantly make sure to make the illusion of having the muscles that he has! Because I'm pretty sure, since you are a girl, you are not as manly rippling as Vega.
For the mask, it seems pretty simple. You could probably use a light wight clay (like model magic or paper clay, maybe even some kind of plaster) to shape the mask the way you want. I'm pretty sure you can sand any of those materials down too to make it nice and smooth too. You'll probably need a nice big strap for the mask to keep it on your head though. My best suggestion, whatever you end up doing, put on the mask before you put on the wig for your costume so you can hide what's keeping it on your head.
For the claws, the bracelet and diamond thing on his hand could be easily made out of craft foam. As for the actual claws, the cheapest way to do it would probably be with cardboard. There's a lovely cardboard prop maker you can find on cosplay.com that goes by the name of featherweight. He makes all of his props out of cardboard, including katanas, which I think could give you basics on how to do your claws. He has some tutorials in the forums on how to make cardboard props that would defiantly be worth checking out.
