Laurie, we have video on almost all our communities now, and the few that don't are budgeted to add it this year. That said, I'm NO EXPERT! If it weren't enough that vendors use different equipment, technology has changed a lot too, so systems we put in a few years ago can't do some of what we added last year. I'd recommend (and I bet you've done this) that you start with refining your scope of work. For example, being able to log-in remotely was a priority for us. Having a recorder with a few extra "slots" for us to add cameras in the future is something we like, but we sometimes back off to get the prices down. I like to refine my list of "MUST HAVE" camera views, as well as the lower priority views that may get nixed if the bids come in higher than I can afford. Also, where you really need CLARITY (like if you want to capture license plate info or clearly see who's at your pool) make sure you get written info on the resolution you can expect. At one pool the image wasn't clear enough to see WHO was at the pool, and you couldn't see the whole deck/chair area. Having areas of the property covered that are far away from each other can add cost, so we sometimes select some areas that we buy a "canned" system from Costco or someone like them that the box isn't in our office, and it records onto a card, and to see the videos we have to go to the box and pull out/save the info on the card. That works where we only need to access the video if something happens, like at an entrance where we don't need to see the license tag info or car descriptions unless there's been criminal activity.
Last thing I recommend: Do a comparison chart of the bids. Where items are different, go back to each vendor and ask them what the difference between their XYZ camera is compared to someone else's model and brand. That let's them educate you, plus it lets them know you are bidding with others! I've attached a sign we place in all our offices, whether we have video or not. It's better than, "SMILE, YOU'RE ON CANDID CAMERA!"