A stock one that is welded up will fit them and I haven't tried the Edlebrock (carb unit) but have heard they will bolt on. The best one to get is the Brodix BD 90 V6 I think that is the number but I would have to go out to shop and verify that number. There are not a lot of intake options for the Syclones. You could always have one built but that is BIG bucks.
Do you have all the hardware and an intake for those heads? Not really sure if I have ever seen a set of 15 degree stuff and I would bet that they would require a set of custom headers. Could you post some pictures? Really interested in the exhaust ports.