I use a 22lb (10 kilo) and a 35lb (16 kilo) with my 34'
catamaran with 25' of chain without a
windlass, and I'm not very fit (but I don't have any serious problems, either). I use a danforth and a
delta...everyone will have their own opinions on which brands are best, but you should be sure to have two different styles so you can switch for different bottom situations (fluke and plow for the areas I cruise). Hope this helps.