Yeah, I would definatelt stay away from the rotary as just because you see the process in the shop doesnt mean you can mimic the results. Go with the PC and be on the safe side. As for the BMW towels and mitts, you could probably save some money by purchasing these online as well. Basically Im sure they are just marketing these towels and mitts towards BMW owners just to make more money off you - Im sure they arent some break-through technology exclusive to BMW's. I'm sure you will do just fine on your detailing, your at the right place
Good luck to you, and let us know how it goes! And :thx for having the sense to get away from your detailer who mixes his products with water 

