Great boat you got there, is the esc watercooled?do u use UBEC?u don't want to go 6s with 8xl motor, u might smoke both esc and motor, go for feigao 12xl, I usually use that motor for 6s setup, its pretty fast eventhough its only 1390kv. Hope it helps
anyway here is a vid of my SV
http://www.youtube.com/watch?v=zeU7u9r3qGg