My .02...I have rigs with both single & dual arb compressors...for 35" tires and smaller, the single is fine. When I went to 37's on the Brute, I had a single in it and it was at the very edge of running at its duty cycle limit & was smoking hot airing up; so I put an additional twin in her (and it doesn't have to be under the hood)...
As far as dual batteries are concerned, only get them if you are running a fridge, and make sure to isolate the starting battery from the aux battery. I was having a couple issues with the Genesis system where the isolator was getting hot & drawing a small bit of amperage, eventually killing the aux battery...I replaced the isolator with a different brand and it works great. In any event, get a quality AGM battery whether only one or two...these won't spill battery acid and won't be easily damaged by all the vibration associated with driving off road.
I have both an Spod & Switch Pros system in two different rigs...both work fine. I installed the Spod in the Brute before joining this forum...and when it came time to put in a switch system into the JK6, I went with Switch Pros...integrity does count, and having been a small business owner, I know how critical word of mouth advertising is to any small business...I don't have any personal experience with Painless, but I have only heard good things about their company...
