Go with Paul Carter at Koerner Racing Engines in AZ.
Here he details one of the nicest 400 engine builds I've ever seen. Paul was kind enough to also include the actual costs for this particular build which are quite frankly very reasonable for the high level of attention to detail paid to both machining and assembling this top-notch 400:
http://forums.maxperformanceinc.com/...d.php?t=785341
Dyno testing the same 400 with amazing results:
http://forums.maxperformanceinc.com/...d.php?t=795059
Don't let distance be an issue here, you'll get it done right the first time from Paul (he has already chimed in above, PY member gtofreek, he won't toot his own horn here).
How many builders dare to freely share every detail on how they do their engine machining and assembly work here? Nobody else that I've seen.