Good choice with the Stag Arms, and thanks for supporting Connecticut industry.  I feel that Stag is the best bang for the buck, they have actually made parts for others like Colt, Bushmaster, DPMS, Rock River Arms, etc.

If money were no object, and you wanted the absolute closest thing to a military M4, I would agree with gunsnbowgal and get a Colt 6920.  But it depends on what you want it for; for a house gun I have an AR carbine and shoot heavy bullets out of a slow twist barrel.  For Service Rifle competition/accuracy the Bushmaster CMP rifle can't be beat for the price.

Let us know how you like your Stag, you're lucky you got your hands on one, all AR-type rifles and 30 round mags are drying up (post-election panic buying).