On Magazines:
For 10 rounders, I stick with the Ruger mags.
For high capacity, the Ruger mags work fine also. However, I have had good reliability with the Butler Creek Steel Lips magazines. I can't speak for any others, but I have 3 or 4 of the steel lips mags and they work well for me. I don't know what the price difference is. I doubt it is all that much.