'67 Mustang Coupe Homework questions

CAR:
1967 Mustang Coupe / Salvage Title & VIN
302 / C4 / 8.8"

The current engine and tranny are coming out and being given to a friend so he can teach his boys how to work on engines.

NEED SUGGESTIONS ON:
1. I want to put a 5.4L in it and want it mated to a manual transmission that will not require a modification to the floor pan.  Which one (if there is one) is a good one?  

2. In the article a Heidts IFS was used, is that best one out there or is there a better one for this application?  I was looking at RC Motorsports because you can buy their IFS piece-meal, which is more in line with my budget.
2A. What is better for a performance application, a typical aftermarket steel cross member (like on the Heidts & RC Motorsports) or a "K-member"?  Have not come across any information on pro/cons on these.

3. I found an add for the FatMan Fabs tubular front end.  Anyone have any experience with these or general information about that kind of setup?

Any suggestions welcome!

Thanks guys!  
67 Mustang Coupe
302 .040 / C4 / 8.8