Guys who are Mini-Tubbed please read...

I'm thinking 6.5" backspacing will be what I'll try..

Don't guess at what backspacing to use. Take careful measurements and get the right wheels the first time. Here is link to the method that I used.

http://www.bigblockdart.com/techpages/wheelspacing.shtml

I measured about 10 different times before ordering my wheels, and they fit perfect.

I just prefer the look of a deep dish wheel. If you like a more modern look, then a deep backspaced wheel will be fine. Also, the disc brake set up that I'm running recommends no more than 3.5 inches of back spacing to keep the wheel from hitting the park brake lever.