I plan on adding a Stebel horn, LED driving lights, 12V socket and heated grips. I've done this to all my other bikes. I've never tried heated clothes.Probably. Someplace theres a post with the watts of the alternator. I did the calculations and as I recall its doable. Check out SymTex heated grips they are $35.
Go for a 12v socket while you are at it. Electric vest is 35 watts to and you can run a slime air pump for flats/airing up.
Plus GPS, charge your phone etc.