I personally would recommend a Glock 17 for several reasons.
1) They are as plain jane as you can get. And IF you shoot someone what type of weapon you use WILL be ANALyzed and arm chair quarter backed to death several times over
2) 17 rounds per magazine
3) Great reliability
I personally am NOT a glock fan but I do own 3 of them because all of mine work all of the time... I personally do not like them because of the grip angle, trigger over travel, and other mechanical issues that I am nit picky about... but they are like an SKS they just flat work all the time!
Based on what your asking for I would strongly point you towards a Glock 17 it will fit all of your requirements..... plus when it goes to evidence you won't be heart broken that they took your nice HK.