I've used Meguiars D151, Optimum AIO and HD Speed. I like them all and feel they all do a great job. However, I mainly use D151, since I have a gallon of it lol, it can be a bit finicky, but I recently used it for a 1 step on a Dodge Challenger and came out great, haven't posted the pictures on here yet. The crazy thing is that I was asked to do a 1 step polish (AIO) at the last minute. I agreed and did the entire car in direct sunlight. (Did start early though)
I've used other Meguiars Mirror glaze AIOs in direct sunlight too and had great success with them. Cant remember the name of them though.
I've never used the ones I listed down below, however, Mike Stoops from Meguiars had great things to say about Meguiars White Wax for an AIO and even said that it would be a great addition if formulated for the Detailer line. Plus it can be bought at your local auto parts store.
Another detailer who you all know, don't know if he wants to be named. Said he uses Meguiars Microfiber Finish Wax for his AIO jobs. So there's that too.
As far as pad, Lake Country White polishing pad work great, I've used there orange medium cut pad too, depending on the color of the car.
Meguiars pads, Lake Country pads, Buff N Shine pads all work well. If uncertain test it out with a medium cut pad or the new Meguiars burgundy pads and if it's to much, then just switch to a polishing pad for your 1 step AIO jobs. Hope that helps.
Tomorrow I have a detail job and if it turns to a polishing job, I will use D151 and maybe the green or orange buff n shine pad.