I am hoping to get some direction on WTF to do with my 80% lowers (Quentin defense) that i finished up almost 6 months ago.  I just have ZERO clue and was hoping for some ideas.  

I have a .223 rifle but no AR15.  Its my HK sl8 thats been converted to a G36.  right now it has a 14.5" barrel with pinned break.  I should have my SBR stamp any day now and its getting sent off to make it a C model *even though i may make it a 10.5" barrel just because I want to run a suppressor on it.  

I have a .308 precision AR rifle.  So a .223 precision rifle is out of the question.  

I have REALLY been wanting to build a PDW and saw that NEA stock.  So I may go that route.  Just kind of sucks cause id have to register/serial 1 of those 80% lowers.  But past that, no clue what to do with the other one.  I have thought of making a "cheap" 16 inch ar15 and just wait till PSA puts a complete upper /kit up for sale around christmas. Anything else I should look at doing?  I was debating getting into 6.5 but after looking up the cost to reload it, thats out.  cost is way more vs me shooting .308.

You want a PDW, how about a 7.5" AR (I recomend JSE Surplus) and a sig brace?
I'm interested in doing a 7.5" in 7.62x39 and I'd use Radical Firearms for that caliber.
2 ARs I want to build my self but don't have yet: mid legth light weight (or government profile) uppers are available from DSA or PSA. Disipator, available from PSA.
Since you don't have ANY ARs, maybe start with an timeless classic, like an A2 clone and/or M4 clone? I've seen M4 kits as low as $400. 20" A2 uppers are getting harder to find.

While the Sig brace is nice to get around the SBR thing, I have no issue doing it as the wait now is about 30-40 days e-filing w/ a trust.  I do want a short barrel but this is where my "PDW" starts getting sketchy because i really dont want anything under a 10.5" .....kinda defeats the purpose of a PDW

If i do a "regular"  AR it will be an M4 style or a fixed stock 20"

I love 10.5s. I'm on my 2nd and 3rd 10.5 builds. one's A1 and the other A3 with MATECH. I just like a standard FSB and M4 handguards.

And now my circle of "what to do" come back to the fact that I will have my G36 as my 10.5" so why do that with an AR.   Whats worse is i have 2 LPK's ready and 1 stock.

Look around for a Noveske Afghan upper....Very versatile and extremely accurate. It can be your do everything AR

 For that price tag it better!