I have been on this site for a while, but this is my first thread. I have pretty decent knowledge of the issued M4A1, and AR15 rifles/carbines platforms. I have owned one AR in the past, aside from my previously issued carbine.
Lower receiver:
Essential Arms J-15-F "Molon Labe" Got it from a local shop for $125+tax. Pretty good deal.
LPK is a Spike's Tactical. Nothing fancy. Included A2 grip, but I replaced with a Magpul.
PSA 6-position stock kit and a Blackhawk ambidextrous sling adapter that a buddy told me about. Installs without having to remove your buffer tube. Figured I would give it a shot.
(Excuse my hairy legs)
Spike's Tactical upper. $99 with military discount and free shipping. What's not to love? Fit and finish are perfect against my EA lower.
I have been going slowly with my AR build; getting the parts I want, and not settling. I plan to add a carbine-length gas system on a 16" barrel, with YHM specter-length Diamond Series free float handguard. Other accessories aren't really set in stone just yet. So far, I am very pleased with it.