I've always bought my gears from Drive Train Specialists. They sold me a higher line of Motives, I think called Motive Performance, made in Italy I believe. I think it might have been $50 more than the "regular" Motives, which if I remember correctly are made over across the other sea. I don't have the car driving yet but the tooth contact was great at set-up, not always even possible with cheaper gears and they've always done me right in the past.

My Moser rearend didn't make it 1 mile without me knowing that the gears were so loud you couldn't even talk inside the car. They said a little whine is normal and wouldn't stand behind it because I had it a year before running it. Took it to Pyle Brothers (specialty is differentials) they put 2 different sets of gears Motives and a set Hoosiers. Both sets made noise. Ended up with a used set of GM off ebay. So far they are the quietest.
Go to Randy's ring and pinion they sell a set that is made by the same company that makes them for GM. They are twice as much but claim to be the best.
I will not by a bolt from Moser again. Its funny how they say a little whine is normal but there are millions of new vehicles that are whisper quiet.
I have been told that the Moser housings are made in China and the quality of the housing contributes to the gears being noisy.