Hi Deth,
It's kind of a broad question, about what is a good diaper and where to get them. First, do you mean locally, where you live. That would be hard to answer, not knowing where you are. Or are you looking on the net? Some good diapers you can order on the internet, would be as follows.
Molicare, Tranquility, Abena.
A good place to find them on the net is
http://www.northshorecare.com/adult-diapers.html
That's just one place. You can try Amazon too, or Google one of those brands and lots of sites will come up.
If you are looking for good AB type diapers try these places.
http://www.abuniverse.com/products/abu-cushies.asp
http://bambinodiapers.com/
I'm guessing you meant disposables only? If you are interested in cloth diapers, let me know, I can give you some good places for those too.
http://www.changingtimesdiaperco.com/
http://www.adultclothdiaper.com/
Oh, and good old Johnsons baby powder is one of the best, you can find it anywhere too.