As one who owns a PMR-30 I can tell you the reason why they don't make double stack mags, they're complicated. Kel Tec did a nice job of making a functional mag but it's not easy to run rimmed cartridges in a double stack configuration. Loading is tricky and if you don't do it right, not 100% reliable.
I'm assuming if the OP is asking about a good .22 pistol he's not interested in .22wmr. It's a fun caliber but more expensive and harder to find.
As for a good .22 pistol, the Ruger mark series have great triggers and good aftermarket support. I've got a mk I from 1964 that's a great shooter. The SR22s also have a solid reputation for reliability. I've always liked the Browning Buckmarks but haven't spent much time shooting one. The S&W M&P .22 also has a good rep.
If I didn't already have an older High Standards Sport King I'd be taking a close look at the S&W Victory, reviews look good and I like the 'vintage' styling.