Are the DVD recorders any good?
Put simply, no.
First, the quality is abysmal. The video is automatically compressed to MPEG2 format onto the disc. The mini-dv on the other hand records raw data to tape (13 GB/s to be exact) and has roughly 5x the picture information. The big problem comes when you try to edit the video on your computer. The video stream from the DVD camcorder is already compressed and then when the editing is complete it gets compressed again resulting in even worse quality.
Second, it is difficult to find stand alone players that can play the mini-dvds, plus you will want to edit the video anyways, so it will most likely end up on your computer anyways.
Mini-dv is still the way to go. Firewire ports are pretty standard these days, especially on Sony computers and with Soundblaster Audigy cards. So the port shouldn't a problem. Some DV camcorders even have USB ports.
As far as price goes, don't spend for features. Spend for quality. Any feature that your camera can perform, you can do on your computer later. Go for as high a quality lens and picture as you can afford. You may only be recording your family, but in the future, I guarantee that you will wish that your recording was a high quality, especially if it starts to decay over time.