I'm sure Revell acrylic will be fine. Before you know it, you'll end up with so many different brands, Tamiya, Xtracrylics, Vallejo, Gunze...
You do not need beginners airbrush. I have got the Badger 150, double action. This is my first airbrush, I have had it not long and I'm glad that I did not decide to buy single action. I thought that single action would be good choice for a beginner, but it is really not that difficult to use double action. Push down for air, back for paint.
I paid peanuts for the airbrush and the compressor so I had no choice. But if I was going to buy one, I'd go for the Harder & Steenbeck - Evolution:
Everythingairbrush Harder & Steenbeck Airbrush Kits
Thinning, hmm. I try to go 60-70 paint and 30-40 thinner. To be honest I don't measure it so it is different all the time but I never have a problem.
I use some old CD covers for testing, it's plastic and you'll see what it's going to look like.