I still don't think you are serious about it but i like talking about equipment so here goes...
If I was opening a gym in a small town in canada I would get refurbed life fitness treads.
They are so easy to work on and so easy to get parts for (gympart.com as an example sells OEM belts that are loads cheaper than life fitness ones) that even if you have a few problems they are an easy fix.
the motors can take serious punishment and you can even send them to places to get exchange ones.
this black model was the first ones but the silver 95T and similar are basically the same machine...
there are seriously many many thousands of these models in north america... they are like the crown vic of treadmills not sexy but solid.
X2
LifeFitness is the best. Great product, great customer support, easy to find aftermarket parts. you can also get an aftermarket kit to put the TV's on the older models
Dont make the mistake of going with Precor. Their niche is ellipticals, not treads.
The refurb idea from jwb is solid.....
Dont be cheap and think "a treadmill is a treadmill". youll regret it.
Globalfitness.com
Fitness Equipment Source......out of Utah. Ask for Mark Clayton. Hes a wheeler and dealer....hell hook you up!