Guitar that blends/contrasts well with Tele for double tracking

If it's a clean tele on the bridge pick up,  try pairing an acoustic with it. If you're doing a few string bends on the tele you'll have to bend the heavier acoustic strings quite a bit to match, otherwise you'll get some bad tuning mis-matches. But it depends on the effect you want. 

On my most recent project, I used two tracks of one Telecaster, one track with each pickup. Worked really well. I feel that the end result sounds like one guitar, only thicker and more interesting.
 
It depends what you're going for, of course.

LOL... I knew something like that was coming
 
For the OP, so much of this is preference for what you want as the end result. If you double-track similar inputs, they will effectively increase the gain (especially if identical). The biggest variation you can create is with something very dissimilar (such as a Gibson humbucker as you mentioned) and then play with placement/layering of those two sources.
 
Bottom line, the more dissimilar the sources are, the more options you have for tone when blending them.