i have a few guitar midi voices on my comp, and they all sound like the lead for an 80's techno/rock band...

Well, I use Guitar Pro 4.0, and the guitar sounds really good.

It has nylon, steel, clean, muted, overdriven, jazz, and distortion guitar. Oh, and it also includes a bunch of other instruments! ^_^

The fact is, the best way to hear an accurate guitar sound is by playing the instrument, or having it be played. And yes, I use GP4, mostly for the fact that you can create practically any sound with enough patience / layers. If you don't have access to a Dropped - D guitar, you can always try to "stack" different sounds in GP4 and try to play them, (really cool is when you drop the entire song an octave to get that deep, bassy sound for practicing alongside...)