Looks great.
You'll be really glad you sprayed everything now, before installing the body, I went the "DIY Lizard Skin" route, but didn't get the firewall sprayed. It made a huge difference and was within budget. I also put a layer of foil bubble wrap between the body and the carpet but may eventually go with the layer of rubber from McMaster-Carr later. I just didn't want anything under the carpet that could hold water.
Now would be a great time to drill-out/remove the supports behind the side panels in the rear cargo area for some Wagongear panels from Kevin or make your own.
I've got one of those 3B AC brackets on mine, works great, I had the parts cut at a local waterjet shop. Looking back I wish the compressor mount holes were a slightly different size to match the compressor holes, but I can't remember whether they should have been bigger or smaller. I bolted the the front and side parts on and tacked it together while still on the truck, then welded it and welded on the rear support on the welding table. Use nylon-lock nuts on the compressor mount bolts (don't ask how I know

), if you use a Sanden 709 compressor, I can get the belt lengths and parts numbers for you.
I'd like to see what you use as a tensioner for the AC belt. My fabbed one works fine and is very simple, but I'm open to better designs. I could post a pic if you want. All the underhood stuff was generic hotrod AC parts. My AC worked great for a while. Now everything I read says my TXV is stuck open. So I'll replace the old evaprator core and TXV (both were used from a FJ) while it's apart so all the parts are new. You may want to replace the same parts while you have it all out.