Since you say you're "very new to owning firearms" and you already have a pistol for CCW and an AR for HD, I suggest buying training before getting another handgun.
But since you asked, I would get a glock 19 before a 17 because the 19 is a solid choice for either CCW or HD--and you can reload with glock 17 mags too. Having said that, I wouldn't suggest being limited to glocks. There are other pistols with very similar controls that might have better ergonomics etc for you.
Surprised to see this thread has lasted a year. :-)
New to owning firearms, but not new to firearms. I was an 11 Bang Bang in a previous lifetime (at least it feels like a lifetime ago!).
Thanks for all the responses guys.