For $1000, you can get an entry level road and mt. bike. If you are really on either singletrack or on pavement, you might be happier w/ 2 cheap bikes than one nice one that is designed for something else.
Another option is to get two wheelsets. W/ the surly, you could probably get a lot of cushion out of some nice fat tires for singletrack. Yet another option is one of the many cyclocross style bikes w/ flat bars, which would at least let you get way back behind the saddle on steep downhills. Only you can know the best solution.
If you are riding cyclocross on trails, though, I would insist on having the extra brakes on the top bar.