I was wondering if the marshall JCM 800 combo is still in production cause all I can seem to find is used ones. If there still makin them could someone tell me where to find them cause my local guitar center only had the heads not the combo.

No, they stopped making original JCM800's in 1990...........the only new ones you can buy are these reissues of the 2203 heads. The combo's are faily common and not too expensive yet on eBay (or used in general)