One option is to get the bike you're looking at (FX) and switch out the flat handle bar for a trekking bar. Another option is just to go ahead and consider a bike that comes with drop bars. If tire size matters, look at a cyclocross bike - my personal choice for me as an all around bike. You can get big tires (700x38 or even bigger) on most of them. I ride a Bianchi Axis witrh 700x32s, not because I am heavy, but because I ride on bad surfaces often. My girlfiend just got a Bianchi Volpe. I have test ridden a Kona Jake. These as well as the well-regarded Surly Cross Check are all good al around bikes that give somewhat road-bike-like geometry with ability to take a big tire. Touring bikes offer this option as well, albeit with longer, less sporty frames.