I have been doing CCTV work for over 18 years now. Not being able to see what the location looks like it is hard to give a sold recommendations. But here is some things to consider.
1. is the guard shack heated and cooled if not don't expect a long life on the DVR.
2. Always use a UPS on the DVR (they are very easy to damage with power surges)
3. Use self contained outdoor cameras for outside they are smaller and cost less and don't need a housing.
4. EVERfocus is cheep but works OK
http://www.everfocus.com/5. I use Honeywell / Ademco
6. on wireless stay away from anything with the words X10 on it......
7. The more light the better the picture.
8. cheep infred cameras only see about 20 to 40 feet in the dark.
9. don't expect to read license plates.
10. always put the DVR in a lock box.
11. YOU GET WHAT YOU PAY FOR!!!
Hopes this helps some.