Good suspension for a '66

[Rhauf]

Im building a fairly high performance '66 mustang with a friend (his car). it's still in the very, very early stages (collecting parts) so i was wondering if anybody here has had any good or bad luck with they want to share? we're going to go rack and pinion for sure. he wants it to handle as good as possible and up to around $6,000 to spend on the suspension and steering.

it currently has a 6 cylinder and 4 wheel drum brakes. we're going to convert to 5 lug and disk as well, which brings up the rear end. Anybody know a good swap-in rear end? i was thinking possibly an 8.8 out of a disk brake explorer and have it narrowed.