I still carry the good ole 4506 in a hoyt swivel holster (no im not a gunfighter

. As far as I know, since the department went to glocks several years back, there is 1 or maybe 2 classes a year to transition back to the beretta and smith platforms. It's called decocker school. There is some interest from the new guys coming on the job to be able to carry a weapon with a decocker but not many since they have been taught that the glock is the cats meow.
The s/w and beretta cougar class used to be called 45. school which was a transition from the beretta 92 to the 45xx platform (starting in 1998 after the NoHo shooting).
My comrades can correct me if I'm wrong but if you went through the academy and were issued a beretta, technically you could carry a 59xx series pistol. however the smiths were not issued. I still see some old timers with 5906 pistols on their belt but they are very very rare.
Nowadays, the 1911 was recently approved (Springfield,Colt and Kimber only) and the classes are 2-3x's a year. However you are required to shoot expert on our bonus course just to attend the class and I hear it is an extremely difficult 3 day training with a high dropout/failure rate. And by the way, you are issued 1 pistol by the city and right at this moment it is a glock 17. If you want to carry something different, you have to purchase it yourself, wait months for an open class and pass the training.
hope this helps...(i know its a little confusing)
dont even ask me about the ar-15 class...2 year wait on that badboy