Either is a fine choice. If you will be working for an agency, what do they want you to carry? If that isn't a factor, choose the one that feels best after trying both at the range prior to starting your academy.
As far as teaching you to shoot, they will do that there, and "learning" anything now (other than safety issues) might just have to be "unlearned" based on how they want you to do it. That is what the academy is for.