I don't think you will find a whole lot of options on factory built 10s packs. You will probably be better off going with 2x 5s packs wired in series. You could just put another layer of heatshrink over the 2 packs to tie them together and you can handle them like 1 pack.
ANother thing to think about is charging a 10s pack. There arent alot of chargers out there that charge 10s well. 2x 5s packs might be asier to handle in this regard also.
EDIT: Pimp is a faster tyepr then me.....