If your going to get a tranny. You might as well spend a little extra dough and not have to worry about tranny problems. I would do the same w/ converters. A yank or a vigilante. On intakes, the 90 would be best im sure, just depends on how much you want to spend. Here's a few charts on the comparison between a few intakes.
Intake manifold hard data - PerformanceTrucks.net Forums