You need something relatively narrow but still MTB strong? If so I would go with the DT470.
Close but no cigar. The OP needs something with rim brake surfaces, the X470 (like other rims that have been mentioned on this thread already) have no braking surfaces as they're designed for use with disc brakes only.
Having a look around, you've got a few options that I can see (though none will be that easy to come by as walking into your LBS or ordering from CRC though)... I'd suggest going no wider than 23mm otherwise it's going to be a pig to get the rim inside a normal road bike caliper brake and will give a 23/25c tyre an overly square profile, and any narrower and you'll struggle to run a 2.1" tyre successfully on it without it folding over at the first sign of a corner.
First up that I can think of is the Velocity A23. This is technically a wide profile road rim (23mm wide vs 19mm or normal road rims), designed to give a 23c or 25c tyre a bit more volume and aid its aero properties. I've heard of people using this rim successfully on CX bikes though too, apparently they're pretty tough. Light at 425g each too
Next you've got the Velocity Synergy. Looks like it's basically a 23mm wide touring rim essentially, 23mm wide again but a bit beefier at 495g each.
The third rim I can think of is the Kinlin XR-279. 23mm Wide again, a 27mm deep profile though (semi-aero essentially) and come in at a claimed 490g each.