I'm thinking that a (gasp!) kit that's modified wouldn't be too difficult. Ie, buy a 'desktop' model, then make the relevant bits to suit. It's plastic, so theoretically it should be waterproof, only a matter of keeping the water out of openings such as the propshaft, rudders, etc.
Weight wouldn't be a problem, since if the hull is even roughly accurate, it should displace much less (to scale) than the real thing, the displacement of the completed model with R/C components to meet scaling should just over 20kg. Which it won't, unless I were to add ballast of some kind, or if I make it with a petrol engine, a LOT of fuel to make up the lost weight.
Shame that Jet turbines are so expensive.......
Anyone into R/C boats/ships
Don't think I've ever seen an RC Ship like a DDG or similar?? Plenty of normal ones though. I built a Tamiya model of the USS Missouri(Battleship) about 12 years ago that was awesome until my ex-wife smashed it to bits, but that's a totally different story. 
