I could make a list of a bunch of guns i have, or "have", or wish I had. Why would one feel compelled to provide that infornation freely? Do you feel the need to show off? Is it some immature game of oneupsmanship?
I have been thinking about getting a polymer lower also. I have heard mixed reviews about them. There are some really great prices out there on the lowers. 9mm should not be a issue, because I have seen a Plum Crazy polymer lower handle .308 with no issues.
Personally I think over the years you'll never be sorry that you spent a little more and got a standard lower.
The biggest issue with assembling an AR isn't so much getting the parts together right - it's getting the right parts together.
US Army 1966-69, VFW Life Member, Retired Geek