BB- Yes I have the solenoid hooked up with my Hi-torque starter. Will post pic. Been in there for seven or eight years.
One other snag with the mini starters is the hole in the bellhousing inspection plate. The snout of the mini starter is smaller that the stock starter so the hole isn't completely filled. They say no big deal but I was afraid a stone may get in so I built a plate type cover. Will post pics.
You found me out, In modesty I try to let on someone else is doing the artwork, but now I've been exposed.

Sled- Things good here, have had surgeries cancelled but still managing with the use of one arm. Haven't been to a store in six weeks, running out of beer. I'll have to get another pallet load.

Bob- Yes those headers do put out a lot of heat. I'm sure I could cook a roast beast dinner under the hood in about an hour of driving time.
With your battery in the trunk you'd have to run some pretty heavy cables up to the starter, I'd ground that battery through the body and frames and also run a ground up to the block at the starter.
MSD starter? Personally I wouldn't put anything with an MSD logo on my car, even if it was given to me. Not after the pain I went through with one of their 'ready to NOT run' distributors. Came pre-corroded, with a pre-bent shaft, same internals as one of those $90 Chinese crap distributors that fell apart on me 100 miles from home. Even the shaft diameter was screwed, larger diameter so I had to spring another $100 for a composite distributor gear with the correct diameter bore. All that just to take the piece of crap back to the store and rebuild a GM original. MSD is the same as the aftermarket crap you mentioned in your other post. Just thought I'd add to your rant.

Of course, all this is just my opinion, I'm not an expert.