Lots of the Guild guitars mentioned above do sound fantastic. The danger with purchasing an old Guild sight unseen is that a lot of older Guilds are in need of neck resets. I've seen many. That means that the guitar is collapsing in on itself; the neck is pulling forward, and the strings are too high off of the fret board for easy playing. It would be a real tragedy for you to stumble into that when buying your first quality acoustic guitar.
Here is an article that discusses proper neck angle on an acoustic guitar, and how to examine the neck angle.
http://www.frets.com/FRETSPages/Musician/Guitar/Setup/NeckAngle/neckangle.html
In a simplified summary: if you sight down the neck, the neck should be straight or almost straight. A slight dip around the 5th fret is o.k. That's called relief and is supposed to be there. Any other humps or twists are a major red flag. Also, when you sight down the neck, an imaginary line along the top of the frets shoud hit just at the top of the bridge, and there should be at least 1/8 inch of saddle visible above the bridge. If the line of sight hits above or below the top of the bridge it is indicative of a past or present neck problem. Don't buy that guitar.
You can ask an on-line seller about the line of sight down the neck, and for action and saddle height measurements, but in much of my experience, they either claim they don't understand or just avoid your questions. In either case, don't buy that guitar.
If you are unsure of what you are purchasing, I recommend that you take along a friend who knows a bit about acoustic guitars and examine the guitar in person.
It terms of guitar prices, $800 to $1000 is not especially high, but even so, you do not want to spend that kind of money and end up with something that will need another $400 or so of work to make it playable with proper intonation.
