My Saiga (AK) loves any ammo you give it. It is probably a much better buy. I don't like it as much as the Mini.
The Russian polymer stuff (Tula, Wolf, Red Army etc.), is not going to work in every Mini 30. I'd spend the tiny bit extra and just try the Silver bear first. The steel cases are more slippery and that is what is needed for the Mini-30. The Wolf Spring company is easily googled, and has a special couple of springs just for the Mini-30. You may not need them. I have the spring for the firing pin, and didn't need it. I'd get the gun and see what ammo it likes. Mine seems average as far as feeding. Above average, in that I don't have failure to fires. Not one. The failure to load has been the problem. Not a big one at this point. I spent money on some jacketed. 200 rounds of 8 dollar FMJ that helps when you break it in. Mine strangely came dry as a bone from the factory. I cleaned and greased it up. This was more important than for any other gun I've had. It wasn't that dirty, but was very lethargic cycling till I had cleaned it.