Welcome, Medic! The Doublestar stripped lower will be fine and it is nice to have a local rollmark. I'd pass on their uppers though as you can do better.
Have you found Agent Tikki's two important threads, the AR-15 Primer and the Deals, Deals, Deals threads? Look at PSA's Labor Day sales in the Deals thread but buy the config that's right for you (which takes you back to the Primer - which should be read carefully).
The biggest issue with assembling an AR isn't so much getting the parts together right - it's getting the right parts together. You'll remember the quality of a gun long after you forget how much you paid for it.
US Army 1966-69, VFW Life Member, Retired Geek