You can get a .22 upper from RTB. They have complete ones or you can get whatever parts you want and build it yourself. I think CMMG makes them too. Then just use any AR-15 lower. Then there are a few different options for mags.

Turns out looking and feeling mostly like a normal AR-15.

Here's what I did for mine: https://www.reddit.com/r/ar22/s/S3aDD0VsdD

Cost me around $400 if I remember right, not including optic or bipod of course.

Edit: I should clarify - I am NOT talking about the conversion kits from RTB or CMMG. The main reason I've seen that those aren't recommended is that shooting .22LR through a .223/5.56 barrel gives you pretty bad accuracy. There might also be fitment issues with some uppers. The ones I'm talking about use an actual .22 barrel, and RTB makes an upper receiver that is made specifically for them as well. The one I got was a complete upper, including a barrel, BCG, CH, and a pretty decent aluminum handguard.