Hello,
Not sure if you have found a solution thus far but Telexper (www.telxper.com) has a few great solutions that will meet and exceed your needs/wants (I have 4-5 year old systems in a few subways in the bayarea). Aside from having lifetime phone/email support for their product they also offer a 2 year warranty on the DVR's and 5 years on a few hardware components. While it is a proprietary solution, all of their systems are PC-based with numerous applications; traditional analog DVR's, analog and digital DVR's, and full hybrid HVR (all digital).