You know, just earlier tonight I was at a friend's house looking at his black chieftech case saying "a black prometia cooling unit would look great under that thing". To me it looked like a good fit but you should check the dimensions on the manufacturers website to make sure it will fit ok.
I'm in the same boat. My black Prometeia unit will be arriving here shortly as part of the first volume shipments into the USA. I wanted to use an Antex SX685B black mini tower because they look great. Same case as the Chieftec, but with an Antec power supply. I'm thinking of a black Lian-Li PC65 case at the moment but I have yet to check the physical dimensions of it.