hey peabody!
welcome to the site!
sounds like you have a fun build project on your hands.
you might get more feedback on basic parts selection and other ideas on a forum such as AR15.com, or another site less-focused on home-building...
that's not to say that you won't get good feedback here, but most folks here are into slightly more esoteric stuff, and posts about the basics may gather a bit of dust at times.
in any event, you're more than welcome here, so join the fray! we'll have you building your own AR-style rifles from scratch before you know it!
on the retro build note, not sure if you've checked them out already, but
NoDak Spud is a great resource for everything retro-AR... i know you said you were not building a true retro, but if anything you can use this for future reference. you know what they say about potato chips?... well....
