That socket would work OK, but you might find it a bit awkward to mount it neatly? It's a good price, but when it comes to waterproof electrical equipment you do get what you pay for IMHO. You might be better off with a surface mounted socket (?), it'll be result in a tidier job, for example it'll fit quite nicely in the panel behind the front indicator (a fag lighter socket will fit but it's more of a squeeze). Here's one of mine...
I've actually got one each side, an ignition switched one and a direct to battery one (which I can use with an Optimate).
Also have you considered a DIN type socket, rather than a cigarette lighter, they are more common place on motorcycles because they are smaller and easier to make waterproof?
http://www.windingroads.co.uk/shop/p...owerlet-socket