Just happened to see this a month later.. I'm assuming you found something by now? It seems a lot of people use the Vintage Air GenII Mini system. Though it seems nobody makes a working replica control panel to match the Countach one, so not sure what people use for the control. (or just hide the VA one somewhere) The HVAC system itself is pretty small; I'm putting one in my Fiero when its done to save some space and have it work better than the 25 year old OEM one.