VA is still listing part numbers 50615, Compact heat w/defrost and 50616, bilevel heat w/defrost. This allows for a smooth firewall. Retail about $200-250
http://www.vintageair.com/cat2007/25.pdf
I had also researched this as an option for my build and found this over at protouring:
http://www.pro-touring.com/forum/showthread.php?t=36612
Good luck-
