My build so far:

UTG PRO 9" aluminum quad rail
Magpul STR Stock
Redfield Counterstrike Red/Green dot sight w/ red laser sight (temporary)
Took off the ugly giant cheese grader Flash Hider and put on a sleeker Muzzle Brake
Two Magpul 25 round PMAG's

Soon to be adding:

ATI Scorpion Recoil Pistol Grip (in the mail)
Magpul AFG Fore Grip (when I get paid Friday )


Here it is next to my G23:








In the future I want:

Geissele SSA-E Trigger
Magpul MBUS Pro Iron sights
Maybe freefloating handguard
Better charging handle
Scope