When I first got my BPPC, I just built a dock out of plastic. Exactly the same area as the underside of the 1200 case and just tall enough to fit a standard CD Rom, which was under the left hand side of the case.
The dock had air intake fans at the back that ducted the air to the trapdoor, where the 040 with its big heatsink was. The only way for the air to escape was up through the trapdoor and front air intakes of the 1200 base and out through the top vents.
All in all it worked pretty good :-)