A couple of things, first Gary Fisher bicycles is a part of Trek, they had a falling out last year, and I guess have kissed and made up, so Fisher is no longer a division of Trek, but part of Trek. Generally all bicycle makers used components by one of three companies, Shimano, Sram and Campagnolo, the last one is only found on mid to high end road bikes. Generally the manufacturers will stick to the same line or lines at the same price point, a $700 Trek a $700 Giant and a $700 Bianchi will all be similar bikes, and they are probably all made by the same Chinese contractor. The differences are generally the geometry, one may have a longer or shorter top tube then another or different angles. This is where shopping gets important, you need to go to several dealers and try as many bikes as you can, see which one fits the closest.
Now have the rear wheel sent to a wheel builder to be properly tensioned for a rider your size, then ride it like you stole it.