If I had to guess, I would estimate about everything is more difficult where you are except for getting cooled off.
Between you and Les, the two of you probably have more grit that half the guys on the forum combined.
If interested, there was information on mine on page 12 here. Balance specs were given. 1400 mile engine that I started with.
https://www.thetruckstop.us/forum/threads/95-engine-build.50739/page-12#post-658280
I have the single t-stat and loaded up a little in the hills of southern Ohio with A/C on and 90-95 degrees out, I didn't need to turn off the air conditioner. That is with an OEM which I believe is 195. It didn't really offer to get much warmer than typical unladen.
An internally plugged...
I replaced the ones in the rear also - 4x6 maybe? They're hard to get to on account of the need to remove the ceiling trim and loosen the pillar plastic but I got it done and no clips broke. The speaker location is fine for metal heads but others might complain.
If I remember right, I left the one above alone and just replaced the lower.
I think mine are Sony
I didn't have to fish any wires but I bought from Crutchfield so I would have gotten an installation kit if it was needed.
I believe you would stay cleaner if mounted forward of your rear axle. Is there enough airflow between the frame and bedside on the passenger side?
Sort of opposite the fuel fill side