I'm going to buy a dumbbell I can use for dumbbell snatches, dumbbell swings, goblet squats, weighted pistols, and any other exercises that I can think of. I plan to do these exercises for conditioning purposes, not for pure strength purposes. Problem is I don't know what weight would be good to start with! I was thinking either a 20kg, 25kg or 30kg dumbbell, but I think 15kg would be a bit light. I'm 175cm, 68kg, and I'm a beginner to these sort of weighted dumbbell lifts. What weight would be best to start with?