I agree with 46! Sell the 350/350 combo and pick up a salvage late model donor. To do the LS swap you are going to need quite a bit of the electronic stuff from the donor, but the end result will be better than what you have going in. Word to the wise, make sure you check all the stuff you might need for the swap, i.e. oil pans, crossmembers, etc. As with any swap, these are the items that start getting into your wallet. The good thing is you get respectable performance, reliability and, hopefully, decent mileage.
Look at OldAir for your AC needs.
Alvin has a great thread on installing seats in his panel. I'm using the stock seats in my burb but replacing the springs with more comfortable foam.
The brakes can be upgraded fairly inexpensively, 6 lug kits are common. I don't know about 8 lug. The 1/2 ton front axle is sufficient for your usage, I believe. Once you swap the tranny, your options for the rearend become fairly wide open. You can source almost any rearend that will fit. If you are persistent enough, you can make anything fit!
My suggestion is this; outline exactly what you want(you've already done this), pick the mods that you want/need, write them down and then, stick to the plan. It's just like writing a business plan. Make it as clear and concise as possible. You know what you want, what you have to buy and APPROXIMATELY how much it is going to cost. It is so easy to get sidetracked and wind up doing something way different than what you started out to do. so, make a plan and follow it!
Hope this helps, good luck!
Mitch
