I tried the Williams Fire Sight combo first - sucks for the Yugo. I'll give them the benefit of the doubt for other SKS models because they are all a little different. On my Yugo the rear sight shifted right and left a lot - useless!
I installed the Tech-Sights TS200 on my Yugo and am very pleased. If you are familiar with the M1 Garand type aperture sight its very similar. The set screws set the sight in place so that it returns to zero when you put the thing back together. I've found that with my 38 year old Lasik improved eyes the weak point in the whole thing is the size of the front sight, which I plan to grind down. Even my Dad's 76 year old eyes can do pretty well with the aperture sight, but he actually used an M1 back in the old Army Air Corps - Riding a bike type thing I guess.
Short answer - I recommend them.