high-resolution outdoor night/day security camera - anyrecommendation

For my home, I want to purchase 1 to 3 very high quality night/day
security cameras.

What I am looking for is:

* a camera where I can extract single frames and produce photo-quality
images

* works well during the day or at night

* at night, I live by a street, and so the cars will come and go, and
I have street lights.

* if something happens, I want a high enough quality image where I can
read a license plate or identify a person up to 100 feet away from the
camera - day or night.

* system will be unmanned

* auto-tracking would be fantastic if it works well. The sidewalks
are probably 50 feet from where the camera will be mounted, and so if
it could track someone walking down the sidewalk (or around the cars
parked along the sidewalk) that would be great

* high-quality: if I'm going to spend $1000s, it would be nice to go
at least 5 years without any problems

* I don't need audio support

Right now I'm looking at cameras from $250 to over $5000. If I'm
going to install a camera, when something does happen I want an
excellent quality image.

Ideally, it would be nice to hook it up to a PC and capture at least 7
days of video before it overwrites captured video feed.

Does anyone have any recommendations?