I went with the castle 8s pack, seeing as it's matched to the esc. I've tried to find some info about mixing capacitors but nobody agrees whether it's a good idea or not.

Anyway, got it all soldered up and ready to program (castle link included with the esc was nice, even if I already had one)... and ran into a problem... my laptop wouldn't pick up the castle link. Tried my desktop, no problem. Went back to the laptop, tried a different USB port... AH!

DO NOT TRY TO CONNECT CASTLE LINK (USB) TO A USB 3.X PORT. It seems to only work on an old USB 2.x port.