i wuld liek to know hwat stage wheels i have and how easy it would be to buy a new wheel, housiong and backing palte....

3 years ago i bought this turbo for a custoemr who never paid, and sat on it. from waht i recall along with markings on it, it was a t3/t4 60 with .48 ar hot side and .70 ar cold side.
so anyway it has been sitting on the shelf for 3 years, and i deicde to put it on my car since it was jsut taking space.
i put it on and start the car and it spins fine, but i am leaking al ittle oil, so i tighten up the oil ins and out adnr estart it its all good, about an housr later i start it for my brotehr in law, and it doesn't spin at all.
i pull it off and find the bolts holding the backing plate are stripped:


so i need a new one of these:



i may want a larger compressor housing and wheel:



and here is the exhaust wheel:


the i bought it from another local business htat is long gone who had bought it through http://www.turbonetics.com aka performance techniques.
where can get the backing plate for a fair price, and is it worth my while ot upgrade anything while i ahve it apart?
tanks for any help.