http://www.ebay.com/itm/16-CH-CHANNEL-H-264-CCTV-DVR-Standalone-Security-Surveillance-Video-Recorder-/120968705370?pt=US_Surveillance_Digital_Video_Recorders_Cards&hash=item1c2a4bf55a
I have been installing/troubleshooting/upgrading CCTV cameras & systems for the last 8 years and this product @ $99 is by far the best bang for your buck. It does automatic port forwarding and remote viewing on any iOS/Android device is a breeze !!! Throw in a 1 TB hard drive and u r good to go. D1 viewing sucks up a lot of bandwidth on your upload speed and I have a seen a lot of carriers data throttle upload speeds nowadays.
Hope it helps !!