Generations METROPLEX: Where can I buy the 3rd party upgrade kits?

I just had my GIGANTIC Generations Metroplex and I'm very happy with it. However, he can be so much more. I heard there's some 3rd party company who made new weapons, hands, ramps, and even a new head for him. Unfortunately, I have a hard time finding where the hell can I buy those things using Google. All I see is news reports but nothing precise.
Can anyone point me in the right direction? Preferably a place with pictures, prices, and where they can take no-credit-card international Paypal.
Can anyone point me in the right direction? Preferably a place with pictures, prices, and where they can take no-credit-card international Paypal.