Boat tailing seems to be an extra expense that you can do without in terms of the cams you are running. Thumbs up on the Jenvey setup, why did you choose DTA versus Motec or McLaren? Depending on what rear bumper you have on your car I would sway towards fabbing your on muffler setup and spend more money on the heads for port matching and flowing. On a sidenote, no affiliation but Steve from Rennsport sells a very slick Jenvey based ITB kit with brain in the neighborhood of 6k ready to go. Depending on what you have and what you want a MFI setup would be pretty mean on a motor like this. I assume with the processing power from the DTA you are going for a crankfired setup which is clean as is.
If it were me I would take the money from boattailing and mooning and put it towards 100mm p and c's for a 3.5 litre motor. Just take a look at the one Henry Schmidt built and see what you think.
http://forums.pelicanparts.com/showthread.php?threadid=164543&highlight=twinplug
It's about 1/3rd down the page, the numbers are awesome. Best of luck and keep us up to date. My motor build is slowly moving closer and closer and I love picking everyone's brain. Cheers!