Ive been shooting with my dad for years but want to get my first rifle on my own for my 21st in a month, I haven't shot in about two years. I wana be able to do some target plate shooting and maybe some deer hunting with this rifle at around 300-600 yards. First gun that came to mind was an ar15 .223. I live in california and arizona so I want the gun to be legal in both states. I know california recently passed some laws about pistol grips and AR's. I wana build a full custom with optics, adjustable stock, quad attachment rail and bipod. What're some things I should look at? Good places to get my gun, what state should I get it in, and the legality of the gun.