I’d recommend an AR-10 or a Saiga. A .223 round is simply crap IMHO and very expensive.
Magazines can be expensive for some AR-10 variants - I would recommend an FAL instead (but then, I used to build them ;>). I agree that Saiga's are a great option when it comes to AKM-type rifles (until very recently, I owned a .223 Saiga that I legally 'converted' many years ago to use Galil mags & standard AKM furniture). I would suggest that .223 is NOT "crap" (civilians are NOT limited to FMJ or OTM ammunition), and it most certainly is not expensive, particularly when compared to comparable .308/7.62 NATO ammo. And of course, I no longer own any firearms, the ownership of which might be affected by any proposed legislation. As always, this post is offered only as an opinion, YMMV, FWIW, etc...
;>)