where to get coolant...

2000 3.8L V6 does any major brand of antifreeze that conforms to this vehicle specifications will do or do I need a specific kind? What do you use/recommend?

If the coolant is green.....then you will need the "traditional" green type.
You can get this from the dealer under the Motorcraft name, or you can get it under several other brand names.
Traditional green is not so easy to find now-adays......
It is NOT the old version that had so much silicate in it that it dropped out and clogged things up.
Traditional green should be changed every 2 years.

If the coolant is somewhat yellow.....then it is "G-05" type of coolant.
This can be bought under the Motorcraft "Gold" or the Zerex "G-05" label.
I converted my '96 over to the G-05.
G-05 is a "long life" coolant.....however, if you don't get ALL of the green type out......the G-05 (or any long life) will be good for 2 years (same as the traditional).

I do NOT recommend ANY other type of coolant (not approved by FORD).
MOST of the coolants that you will find out there are "silicate free" which are not what our windstars were designed for.
Here is a good website for the Zerex coolants.....that will show you a lot of information.
http://www.valvoline.com/zerex/

I don't believe the coolant is green in color, I would have to check again to make sure. Reading your post it makes a little more sense to me as I was confused by the owners manual directions about what to use and what to avoid.
Reading the manual again I found that it warns about to "Use only Ford Premium Engine Coolant E2FZ-19549-AA (in Canada, Motorcraft CXC-10) or a premium engine coolant that meets Ford specification ESE-M97B44-A".
Whatever those numbers mean I just hope I find them on the coolant container's label at the store.

That would be the green coolant.
You kind of have to look for it.
I would visit Peak's website and the Zerex website to learn what their green products are......then visit the auto part stores.......Carquest and Napa.
I found that auto part store clerks are pretty clueless about antifreeze......to put it mildly.....so do your research ahead.....and if they don't have it.....move on.
A coolant that says "silicate free" on the label is NOT the traditional green.

FORD says to use ONLY the green.....and not any other.
My conversion to G-05 in my '96 is NOT FORD approved.....although I am quite confident in it.....I want to be clear as to what FORD says.....and let you decide for yourself.

At some point....FORD did use the G-05 coolant in new windstars at the factory.....I do not recall what year they started doing this.

Of course......pay close attention to the label.....coolant comes premixed and concentrated.
If concentrated.....you need to us 50% coolant and 50% distilled water.
Tap water can cause major deposits in the system.....depending upon the water source where you live.