I like the TWM because they are 58mm, but Very Cool Parts sells 460 stacks as well. I'm planning to go EFI eventually, but first I need to get the car on the road. If you go EFI, you are blazing the trail and it will be a project with little help. Most of the aftermarket injection seems to be done by the small block guys. Drag racer may be a good source, but their programs will probably not be useful as they have a totally different purpose.
Here are some links to TWM and Very Cool Parts. TWM has a link (somewhere) to a number of ECU makers as well.
Very Cool Parts
TWM Induction