Louroe is good stuff.
Crown PZM-11LLWR is a good outdoor mic.
ELK-800 Amp connected to whatever speaker you like will work well most of the time.
For an indoor application, if you are prepared to do some soldering, you could consider using the Audio Technica/ Propoint Boundary Microphone listed at $74.99 on Amazon under musical instruments. For the loudspeaker, you could consider using a normal mains powered active loudspeaker like the M-Audio Studiophile AV-40 Active Studio Monitor speaker listed on Amazon at $134.99, in conjunction with a 24V/120V step up transformer such as the Honeywell AT72D1683 listed at $26.38 on Amazon. To my knowledge, all the brands are well respected.
The application is indoor and vandal resistance is not a requirement.
I generally recommend Louroe, especially if you're looking for intercom, because they have a box built just for that. I know several integrators have used that model and like it, too.
It would be helpful to know whether your application is indoor or outdoor and whether it is important for the products to be unobtrusive or vandal resistant if used indoors.
I have used ETS Microphones before with Sony cameras and they work well.
Isn't Louroe the main source for professional mics and speakers for surveillance cameras? See our Louroe review.
I am sure others will have more specific recommendations.