1. Power cable
That issue will resolve itself as you give up and go with something that works. I've seen clients want this or that and we have to give them time to process what is available or what it costs to hide wiring or install another outlet. After they get through that then the work can begin.

2. Memory card use.
As to the memory card those are a 20 buck item and sharing it with other device is a BAD IDEA. Install it and let it be. If you want to create more support, sure, take it without complaining later.

As to bigger memory why didn't you go with some HDD recorder. Here the wired camera 500GB with cameras are cheap as exampled at http://deals.woot.com/deals/details/05f48227-f0b9-4373-bcfc-e458499bb9c1/zmodo-4-ch-cctv-security-dvr-outdoor-ir-camera-system-500gb-hd-network-view (190 bucks) Your system was 415 so plenty left over for a display or just watch it from the network.

3. 2.4GHz links.
Be sure you can return those wireless CCTV systems. If you've seen what I see you know that they are subject to interference as well as interfering with a lot of WiFi systems (in spite of claims to the contrary.)

4. Other systems.
If I wanted to setup something new I'd look at DropCam again.

And keep shopping. - New!
http://www.woot.com/plus/zmodo-security-5 shows more common solutions for cheap.