I have purchased cheap mainspring winders in the past and they have been terrible. In the end I plumped for the 5356 Set. It serves both left hand and right hand mainsprings. But I find mostly that I use sizes 4, 5, 6, 7, 8 and 9
Most swiss movements use the clockwise wound handle and cranks and I find the anti-clockwise handle and cranks useful for Japanese (like Seiko).
There is a special ETA set, but I find #8 is OK for the 7750 and using size #7 with #6 crank (carefully) works well for 2892-A2 and 2824
The rest in the set I rarely use.