Well, I weighed in at around 240-250 when I started with a Trek 820 and I still love that bike. I would say that for a guy of your clyde-ness (no insult intended, heck you are riding to get fit anyway, right?) that you go with solid fork. My 240-250 was enough to compress the suspension pretty dramatically if it wasnt constantly maintained. And it was AWFUL hearing that fork click up and down all the time since I never took care of it...
Also, the more upright ride on the navigator might be better suited to a new rider. Sometimes the saddle-handlebar drop can be awkward when starting out.
FSC