Double tracking is primarily done in rock/pop/metal music. Similar to double tracking is reamping. There will be lots of opinions on this for you from others.

Two mono tracks are far more useful/flexible than 1 stereo track. Unless recording a synthesizer, almost always use mono tracks. You can then pan them however you want. With stereo you're stuck with hard L/R panning (yikes).

Another benefit: lets say you record guitar in stereo then double track it in stereo. Now you have some excellent panning options...
Guit1: L100/R30 Guit2: L30/R100, (my fav) or...
Guit1: L100/L10 Guit2: R10/R100 etc....

Note for above: all the hard panned channels L100/R100 would be at lower volumes than the more center panned channels.

On a side note: if the guitar has its own mic/pickup system, then by all means, connect a cable and record that as well to its own mono track along side the other 2 stereo field mono tracks. You now have even more options. You can use it or toss it if it doesn't do anything you like.

sidenote: I'm not a big fan of double tracked AC guitar, unless the 2nd guitar is played slightly more like a 2nd guitar part. But to answer your question directly, having stereo for both original and double tracked guitar is not, in itself, overkill. As long as you use mono tracks and panning you'll have that much more freedom to get the sound you want.

O.K. Thanks.

What is the instrumentation of the song?
This is very important.

If it's pretty much just acoustic (and voice?), then by all means go buck wild.
If this is going to be mixed w/ a drum kit and other instruments...
I don't like 4 tracks for one source, unless it's drums.
The exception would be double tracked electric rhythm guitar.
But again, not if the mix is leaning towards dense already.

You can try it - it may be what you need.
Just be aware that having that many tracks for one source can bite you come mix time.

If you are going to try this, I would definitely make sure it was coincident pair - xy, blumlein, or ms. And even then I would listen to it with one track of each stereo pair turned off. Two stereo pairs runs a big risk of turning into mud.

soapfloats, post: 356594 wrote: What is the instrumentation of the song?
This is very important.

Curiously, I have not decided yet. My intentions -however unorthodox this might sound- is to get a very respectable foundation track of one unaccompanied acoustic guitar, that could stand on its own if need be, and add other instruments if it suits or adds something. I realize there are obstacles with this approach, but I plan on working through them.

try using M/S recording and see what that does !!!! its quite beautiful...............

Monomonomonomonomonomonomonomonomonomonomonomonomonomonomonomonomonomonomonomonomonomonomonomonomonomonomonomonomonomonomonomonomonomonomonomonomonomonomonomonomonomonomonomonomonomonomonomonomonomonomonomonomonomonomonomonomonomonomonomonomonomonomonomonomonomonomonomonomono..............

That is all from me ;)