I get them from Ted Longshaw he brings them into the UK he doesn't have an online store though you have to call him, the number is 016898553130
If your in the states
R/c nation has them.
Hot Bodies Lightning 2 Pro carbon, Mega 22/30/2, MMM, 4s3-5Ah.
Tamiya F201 carbon, Mamba 7700, MM, 2s A123 2.3ah.
Xray XT8, 1518, MMM, 4s5Ah.
Lots of boats.
fastelectrics.net