Another suggestion to consider a view (large format) camera with a roll film back. You can probably pick up a 4x5 rail-type large format camera, standard lens, and roll film back for a comparable (or lower) price as a medium format or 35mm format tilt/shift setup.
WOW! Thank you all for this wealth of information.. I seems like MF with a tilt shift option is CrAzY expensive.. I've been checking out a few of the option you guy's have pointed out and they seem simply unreasonable! Going for a 2x3 view camera really does seem like the only reasonable option but I was hoping to keep some of the portability afforded by an MF system. I might have to stick to a regular MF for now (with Jon's rubber coupling idea.. That seems fun!). And once I go for a view camera, I'll probably go straight to a 4x5 (or bigger) kind of system.
But if you have any other ideas? I'm all ears!
Once again.. Thank you!!