The Glock and the Sig are both great pistols and both very different. The G19 is a compact gun while the p226/mk25 is a full size gun. If you want to keep with the "same as the military has" vibe but want the same size gun as the g19, check out their M11 that they just added. It's the same size as the p226, so its more along the lines to the g19 in size.
SIG 1911 .45 ACP
SIG P229R E2 SRT 9mm
Beretta BU9 Nano 9mm
Beretta 84FS .380 ACP
PWS (Primary Weapons Systems) MK114 5.56 NATO