Safe bet is a colt 6920/6720. M4carbine.net for tons of info, read but don't post. DD, Lmt, BCM are top notch as well. light weight profile and mid length gas systems are, IMO, nice touches. iWC for mounts/lights, LMT rear fixed sight.
there is a nice 6920 and a LMT in the classifieds right...
SOLD
Just bought this on sale for 89.99 from PSA, and I don't need it as a spare ATM. My impulse buy can be yours for the same price, 90 shipped. Full auto, MP marked, in the PSA tube, new in box.
PM, no pics. Thanks. NWI local pick up, if you prefer.
I don't have any experience with Kahr or a single stack sig, except the P225, which was awesome, but too large for it's capacity. Maybe you need a better holster?
XDs9.
G19 Dale Fricke Gideon elite, used only a few times 85$ shipped
G17 spring kit, incl. Guide rod assembly (glockparts or glockmeister, I can't remember which, labeled '1') 15$ shipped
G17 safariland level 3 model 6270-83 duty belt 2" attachment, used but functional (will figure out part #...