I say, build you own CCTV setup. All you need are some cameras, a CCTV card, a cheap PC and some HDD.
A 16 channel card is like $120. To monitor remotely, you can setup Terminal services (Remote desktop connection server services), but you need XP pro. IF you're going to use RDC to monitor, I suggest setting the recording at 10~20 FPS, because the RDC doesn't work well with video playback by itself, you need to setup VLC with remote video playback.