If its helpful. Here is a couple of cheaper sanders I've used with good results. My electric Polisher/ Sander is an older version of this one (Chicago Electric vs. Bauer) and its worked fantiastic now for 8 or so years. For a cheap-o its actually really good.
https://www.harborfreight.com/8mm-ra...der-64528.html
Given my challenges with a small compressor, I've also used this little guy for getting into tight spaces and it works well too.
https://www.harborfreight.com/air-an...der-93629.html
Like I mentioned before, in commerical settings I exclusively used Depont products, usually Imron for planes and helicopters. But when I'm messing around at home or painting my friends vehicles, I use Eastwood products, House of Kolour products; or GCI products when I'm doing vehicles for my cousin's WW2 car club. Just depends what I'm painting and its intended use.