You've gotten off to a good start, Chris. Nice choices.
I don't consider any Glock a "collector" piece, however. More like a tool or appliance.
To have a great collection, you'll need some iconic WWII and Cold War guns:
Browning Hi Power
MP40 (ok, at least it shoots 9mm!)
HK P7 PSP or M8
Sig Sauer P226
Ruger Super Blackhawk .45 Colt or .44 Mag
S&W Mod 27
Mauser Werke, Schmidt-Rubin, Colt, Walther, HK, Weatherby, Browning, Ruger, Beretta, Savage, Bushmaster, Marlin, Mossberg, Remington, PTR, Saiga, S&W, Sig Sauer....a few friends of mine