Hey wahturi. The last Hi-cap mag was made prior to the Sept 13, 1994 ban. You can still find them new in the factory wrapper, but like Beta_MO said they are expensive. I have 2 Ramline 50 rd mags I bought in 1986 for $12, now are $85 to $149 each. If you can find a 25 rd Buttler creek Steel lip, it would be the best Hi-cap, but they run about $50 -$65.
You will not find a more reliable mag than the ruger 10 rd. Unlike the other plastic mags you can dissamble to clean, and adjust the rotory spring. They go for $9 to $12, just about everywhere. I have seen clips which connect 2 or even 4 mags together, like jungle clip, just rotate each 10 rds. I carry 50 rds in 5 mags, in HKS speed loader pouches on my belt.
The big thing about the plastic lip mags is the mag has an ejector, and feed cam, which becomes worn, and jams will occur. Check out this thread:
http://www.perfectunion.com/forums/showthr...ghlight=ejector