The first thing to mention is that it all relies on your budget and whatever current items you may have.
1. I use a camcorder that records on regular DV tape.
The DV input is for digital transfers, whereas the AV input is for analog transfers. You will most likely need a device with AV INPUT. The majority (if not all) bullet cameras will be analog.
My video camera is an ancient Sony TRV-33E.
2. My bullet cam was purchased at http://www.rfconcepts.co.uk/.
Only a few months ago, there was a discussion about a bulk buy/discount from another firm on bullet cameras. A search on the forums should provide results.
3. The finest that money can buy
4. I use normal AA batteries in mine, although bullet cam manufacturers offer various possibilities.
5. How long is a length of string? I'd think a bullet cam costs between £100 and £150, plus the cost of the recording equipment.
6. If it's from a DV camcorder, use a firewire connection to transfer it to a capture/video editing tool (Movie Maker in Windows will handle it) on your PC. After that, edit your footage. Then convert the finished film into whatever file type you choose to use (for example, WMV for web or MPEG2 for DVD, etc.) and then use a DVD authoring application if you intend to put it on DVD.
Obviously, if you're utilizing solid state devices, the capturing step takes less time and is just a matter of moving data from device to PC.