If you are going to do the two position one, I would have to say the Wisner is far and above the others in quality and workability. They are the only ones I use now. As for the three position ones, stay away from the Gentry or the Dakota. Go with the Lapour.
As for the buehler type of safety, the two and three position ones are far superior as safeties go. The lever comes up too close to the scope and when wearing gloves in cold country, it is difficult to operate them.