Honestly Jake, if reliability is a concern, you have to change transmissions. A strip only car can put up with trans failures every so often. The 4R70W seems to be the only good choice right now for these smaller trucks. If you had an F series sized truck, there are two better choices for that.
If you do want any great street use, everyday use etc, then A/C is needed. I wouldn't cut out the AC ever unless I lived in Canada or farther north. That is required with any modular Ford engine. Just the huge number of swap issues makes those too much trouble.
If speed is the goal, the smallblock Ford is really the best. It has the most parts available inside and out, it's cheaper to build, and very reliable. Everything except the 4.0's will have big issues for the headers, and the cat pipes if you have 4WD.
Commit to your goals, identify the big problems, and then get on it. You should pick the brains of Troll's brother. I think you would trust his experience with the 302 trucks, and he can steer you to what the big issues are for racing. I'd concentrate on building an engine with the best heads, intake manifold, and the camshaft custom made for them. I think 2.0HP/CI is the limit, Jay Allen proved that with his 347. Find the parts for you that will survive your goals. Have fun and keep us posted.