What are you confused about? It sounds like a lot of make up companies are coming out with their own forms of mineral powder foundations. I tried bareMinerals first and I have stuck with it. Some people have an allergic reaction, though, so I would go to make up counters in department stores and test different ones out.
You can also do a google search and I think some online mineral make up companies will send you samples.
I have oily skin, also, and I find it helps the most to always moisturize and use primer before putting the powder on.