I'm needing to get into shape, & thinking a bike is a good way to do it. After comparing various bikes (Trek 300 & 7300, Giant Cypress LX, a few others), I'm leaning towards a Raleigh SC200. I'm a big guy, 6', 300lbs, so I need a fairly sturdy bike. Riding will be about 95% roads & paved trails, but could occasionally be used on things like forest roads & nice trails. No serious off-road stuff. Any advice?