[BR3W CITY]

If your search blazer tanks they can show you how they are setup. Some guys just toss it in the bed to make things easier for a while. Get rid of the in cab fuel tank. I run a fuel cell and you can usually find them for a reasonable price. Its mounted between the rails at the far rear of my truck.

If the trucks are 2wd then you should just be able to slot or re drill holes on the cross member to fit it up. You'll need to get a driveshaft made to the right length and with the right ends on it. You can re work an existing harness, or have one made. If you have the whole truck you already have the harness to start. Since your PCM should already match your engine and trans you may not even NEED a reprogram just to start it, but I would suggest removing emissions components and at least getting a mail order tune.
Sounds like you have alot of what you need, and if your not looking to build a hp truck, you can probably finish your bare swap with less than 2k. Once you add bells and whistles etc, costs go up quick.