Plenty of options. Speaking of Suunto, which just happens to be my favorite brand and is easily available almost anywhere on the planet, I believe the A-10 would make a fine backup compass. Of course, there are the A-20, 30 and 40, each a step up as far as the bells and whistles go. It all depends on what features you're looking for.

Another excellent choice would be the Arrow 20 (or 30). Very similar but somewhat more of a competition compass.
Arrow 20

Or even the M-9 if you like the idea of wearing a compass on your wrist. Easily the best wrist compass I've ever seen:
M-9

Though as you're probably well aware yourself, in the field where accuracy and reliability really matter nothing beats a mirror compass. Preferably one with a fairly large bezel (conducive to precision). My primary compass these days is the Suunto MC-2 with global needle. Not only does it work anywhere on the planet, the needle sets super fast and accuracy is superb. It's the kind of compass I wouldn't mind betting my life on in a serious situation.
MC-2