Do fleet vehicles have any options at all?

They usually have all the bells and whistles (at least rental cars do).
You can often by one with very few miles and a very recent model year.
If you are in the US, try "carmax.com".

What are you looking for? They drive.

It depends upon the spec, but police cars are optioned with engine/transmission options like oil coolers, etc. that are part of the package sold. Rental fleet spec cars tend to be middle-of-the-road with respect to options packages, few are fully optioned.

What ever you want on them