As much as I prefer the .308 cartridge to the .223, I’d start with an AR-15.
It’s inherently accurate. There are a bazillion accessories you can drool over. You can add different uppers and otherwise morph it all sorts of ways. The one you get would probably be better quality than the .308’s you’ve listed (debatable though – and obviously I’m not referring to an original FN or H&K). And, most importantly if money is an issue, the ammo is much cheaper - you can shoot it a lot more.
Also, it’s the one that the anti’s are most likely to try to get banned in the future. I’d get one now. You simply can’t go wrong selecting the AR-15.
Your second rifle should be a .308.
I agree strongly with Forest’s first post but I might quibble with his second. As Julian Hatcher (I think) once said: “only accurate rifles are interesting”. If it’s an AK or nothing, then get an AK (groan!) – otherwise, for crying out loud get an accurate rifle, no matter what caliber!!