Hello, Andyman85, WELCOME to the Forum, and congratulations on your growing family of Glocks!
Personally, I have and love the G26 and G30, perfect size (once you put the grip extensions on) for easy concealment, plus you could use G17 mags in the '26 or G21 mags in the '30, a task made especially easier with slip-on extensions like the X-Grip.
I too have recently been in the toss up between 9mm and 45 (even looked at a 1911) before settling on my glock - I chose 40 cal right in the middle - more fun to shoot IMO than the 9 (a little more to shoot tho) - consider this, if your like me and being this is your first glock you will want to shoot it alot! I went with the 40 its mid range price makes it a pleasure to shoot also I think it will make a great EDC and also has toe option to shoot 9mm the best advise i can give is from my own personal experience - go to the range rent a few and find out what you like best! Keep price and purpose in mind while shooting