High capacity flash memory
Regarding SD royalties check out this post.
Do I need to pay SD Royalties

Most decent companies will offer samples of their products. You won't lose out by asking and most vendors understand that developers need samples before committing to a large purchase.

Note that I believe some vendors may have already paid the SD royalty cost so it would be in your interest to ask your memory supplier if royalties are required, otherwise you may just end up topping up the SD association's bank balance for no good reason.

EMMc cards appear to be very very fast although because they are new and haven't yet been widely adopted like SD cards are at the present...you'd need to weight that up in your design.
Hope it helps.