Making a Trail Rig

[Patriot]

Hey fellas, I am going to be making a trail rig this year and will be looking for a K5 Blazer as my foundation.

My questions are..

Have you guys made a Blazer trail rig before?
What is a better tranny, a SM465 or Auto??
What is a good tire size and lift?

I have 2 1 Ton trucks I will be parting out, a 4x4 and a 2wd. Both are duallys.
I want to use my Dana 60 front and will need to find a 14 Bolr rear(unsure)?? I am unsure about the rear off of my donor truck because it is a Dually rearend(it is a 14 Bolt dually on the truck). The other truck is a GMC 30 Camper Special with the 10,000 GVW Dana 70HD. I can't use this axle because it is also a dually, correct????

So in short I want to build a Blazer with my Dana 60 Front and don't think my dually rear ends will work for my Blazer(I will be looking for one soon).
The 4x4 Dually also has the SM465 and 205 T-Case. I want to use these but what do you guys say?? By the way the donor trucks are both 1979s.

Thanks in advance fellas.