Jumping about a bit aren't you. Other day it was a submersible.
Lot of information on 1/350th Typhoon conversion here- http://www.rcgroups.com/forums/showthre ... ht=typhoon
A cylinder will be similar, just a bit less space, you could always fit two cylinders side by side, like the 1:1 versions.
But I would work with something larger personally. Small subs have novelty value, but that novelty soon wears thin.