Dude...!!! build it with the parts kit you have..!!! if you dont like it and it dont work out then go out and buy a better one... if you dont want the hassle then go with a PSA or a DD or even better get a STAG..
but WHAT EVER YOU DO..!!! if you dont want that Generic one sell it to me for $25 bucks... at least you make half your money back and i'll let you know if its anygood or not..!!!
serously though...
Stag LPK is the one of the best out there so i hear..!!!
DD next on the list
and PSA as an Old Faithful..!!!
unless you go with something that has a match trigger group..!!!
BTW: you got a nice start there and its looking good so far.. you got some quality stuff there... how do you like that JD lower...? that is one of my favorite Lowers, i really like the way the Mag well is flared out a little...