Fuggedaboutit as far as front suspension forks. Heavy and many are unrepairable. I'd also stick to MTBs, given your SOH requirement. They look proportional in the smaller sizes, where the short seat tube hybrids look kinda funky. You'd probably want a 15-17" frame.
Run 1.5-1.75 wide road slicks on a MTB and you will have a nice road bike with a longer wheelbase. Bianchi Grizzlies run long chainstays and the Marins do as well. But the recommendations above for Specialized and Trek are fine too.
If you can act quickly when a new bike is posted on craigslist, you can find candidates for $25. Otherwise, be prepared to shell out $50-$150 for a decent complete MTB. I recently bought this minty PDG Series 50 for $40. Frame is small but the parts are great, and the chainstay is designed to look bent.
Lots of ideas in this thread.
http://www.bikeforums.net/classic-vi...nversions.html
Here is my converted Miyata Terra Runner. I call it a poor man's LHT, as it cost me about 1/10th of a new Surly. I find I ride just as fast on the 26 tires as I do on my 27" and 700c upright bikes.
