Was looking a few years back to get a dedicated 22 upper. Seems like for a while there were a few good options, perhaps Tactical Solutions among the best. PSA has them occasionally, but more recently hardly any options seem to be available. Read some good things about the CMMG conversion kit…and my neighbor who shoot a lot had great things to say about it, so I recently pickup up that kit with 3 mags for under $200. We’ll see how that goes!