Site is a bit tricky. They ARE out of most uppers but will get them in eventually. If it were me, I'd grab the complete PSA/Magpul/Blackhawk lower for $240, the nickel boron BCG for $190, and hold tight until they get more uppers in or find another you like. Only negative I've found on their 308's is their receivers don't use the same parts kit as say DPMS--need to run PSA or PTAC parts kits in their stripped lowers. Since you are buying the lower flat out assembled, shouldn't be an issue.
I linked the fully assembled PTAC they have for sale for $700, but I'm not gonna vouch for it. PSA stuff seems to run great--PTAC is another company (shrouded in mystery, but supposedly PSA acquired them at some point--not sure). PTAC is the "budget" stuff. Not sure how their 308s are but I've read mixed reviews on the PTAC 223s. Triggers can be worked on, but you don't wanna buy a complete rifle only to have to replace the barrel....
Alternatively, I think they have the parts up you could build your own upper. But again, if it were me, I'd get the lower, get the BCG (NiB is a lot nicer than the standard phosphate), and hang out til they get more stuff.
Oh, and I would not hesitate to buy their "blem" stuff--not usually stuff you'll see and certainly won't impact they fit or function of the rifle. I picked up a couple of 223 blems and still can't figure out where the defects are.
COMPLETE LOWERS:
ptac 308 $180 PSA classic blem lower $200 PSA lower with Magup stock, Blackhawk grip $270 PSA lower with Magpul Foliage stock and grip BCGS
PSA nickel boron bcg $190 PSA BCG $160 COMPLETE RIFLE
full PTAC 308 for $700