Difference Bewteen Panasonic PV-GS83 and GS85

But I've never heard of or seen this PV GS83 (your link for it didn't work). You sure you don't mean the PV GS80 (last year's model)?

I shopped around for about 3 months online, then in stores - as far as I can tell, to get all the features I'd want in one camcorder, i'd have to spend at least $3,000.00 for a stripped down prosumer model. But I couldn't find complete specs for any cam anywhere; they pretty much only tell you what they want you to know

The PV GS85 DOES NOT have a manual focus ring, contrary to what the specs on that page say. Rather, it's just a screw-off ring for accessorising your lens.
It has a slot for an SD card for still pics, on the bottom. But the maximum possible resolution pics are so small, it isn't worth messing with.
Still, you need to have the card installed, because the built in light won't work without it. And the light isn't really bright enough for anything but using close up.
It has a stereo zoom microphone built in, with the option of recording in either 12 or 16 bit sound, and wind reduction, which also reduces internal noise reception. Bad part is, the mic zoom control is in the same slider switch as the optical zoom, so unless you're zoomed in tight on your subject, you'll also be picking up a lot more noise/sound from everywhere.
It doesn't have the 3 CCD chips for better color in low light, but it does have several manual presets for different lighting conditions, that do a fair job of compensating most of the time. but they have to be programmed into it through the onscreen display with the "joystick". The only external manual focus adjustment is through the same button that selects between manual and automatic. There are several other manual settings you can make, but they also have to be programmed into the submenus on the screen
Forget about the digital zoom, just turn it off and don't use it - it's only "simulated", like cropping and enlarging a photo on your computer.
Likewise, don't use the LP speed for recording, as it reduces the quality, and the whole point of using the miniDV tapes (THE industry standard)is getting the highest quality, uncompresed AVI files with a steady bit rate of 29.97 bps ( as opposed to MPEG files from Hard Drive or miniDVD)Instead, buy some 80 minute tapes.
The optical image stabilisation is a good thing, but don't expect miracles - use a tripod, or even just a monopod with feet.
It also has a viewfinder, with a much smaller LCD screen inside, which uses less power than the external screen.
The box I got didn't have any software with it (didn't need it), but did include the power cord/battery charger, a USB cord, and a composite A/V cord, and a 1 hour battery. The jack for the A/V cord is out only, so you can't record from your VCR or TV into it. But you can use the firewire/iLink/IEEE1394 to move your edited video from you PC back into the cam, either onto the tape, or play through the A/V cord.
The USB is for uploading stills only, not video, or for webcam.
The jacks for the power cord, USB and Firewire are in the area that the battery snaps into.

Personally, I'd recommend you spend a bit more, and get a cam that you can record into from analog devices like a VCR, VHS or 8mm camcorders, etc, and them capture to your computer through the firewire.

I bought it primarily for recording live music. I've got some of my first videos posted online, and you can see for yourself how well its done (though I hadn't quite figured out the manual focus at the time, lol) at :

Atlanta Rhythm Section
So Into You
http://www.youtube.com/watch?v=AE6d2fUdnA4

Microwave Dave and The Nukes
Hey Little Girl
http://www.youtube.com/watch?v=azL_4iYNNMI

I'm looking at these as well. The main differences I've been able to determine are that the 83 has:

autofocus ONLY, while the 85 has auto and manual focus;
USB 2.0 instead of the 1.1 on the 85.

The 83 also has a feature called "still picture recording" which is, I believe, the ability to snap a picture to tape rather than the SD card.

In short, basically, they are the same. If you need the ability to manual focus, go with the 85. Otherwise, the 83's feature set is a little more robust. BTW, Costco has a $50 instant rebate on the 83 through the end of July. Price there, with rebate, is only $249.