Box,if you ride your longboard like Jackson Close go for a 10.6 PSH wide.
If you like the cruise aspect of longboarding go for the Naish 11.4.
I base my opinion from riding longboards for the past 20 + years and prefer to
attack a wave than cruise,I started out on the 11.4 Naish and after two months
I went down to a 10.6 PSH wide. Now everyone will have an opinion and this is just mine

mac