I haven’t messed with many but have seen some pretty crummy plastic “kinda looks like an AR.” ones.
What is the “style” you are looking for exactly. Just a .22 rimfire with an abnormally high sight height vs bore centerline or just something black that doesn’t look traditional?
The first ones I remember were in the early-mid ‘80’s like the Italian EMF AP-74 and the fairly rare Federal engineering XC-220. There have been some less than reliable ones out there since then though.
I only have one .22lr AR upper, I bought to introduce a Young new shooter to the platform and the sight system (KNS front/NM rear), I used a CMMG “dedicated” upper on the same lower they were going to be shooting with the centerfire upper.
Figured it would be the most identical, no crummy trigger or different locations of cheek weld/ sight height, safety, mag release, etc. vs something that’s not a “real” one, because it is a real one.
I went back and forth on just a chamber adapter conversion but none of them shot as well as I had hoped for.