First and foremost, congratulations!
Second, welcome to the Firing Line.
Finally, if you have some ideas of where or for what department you'll be working for, I'd suggest that you contact someone there and ask about what sorts of pistols are accepted as duty weapons. If there's only one accepted firearm, then nothing we say here will make a hoot's worth of difference.
A gunfight is not the time to learn new skills.
If you ever have a real need for more than a couple of magazines, your problem is not a shortage of magazines. It's a shortage of people on your side of the argument. -- Art Eatman