Disclaimer: I know several of the guys who make the knives that I am about to recommend. However, my recommendations are based upon a ton of real world hands-on use and abuse rather than these affiliations - but I don't want to piss anyone off so please consider the following to simply be my opinions.
If you want a totally bulletproof general purpose knife in that size range my first choice would be a Bark River Bravo 1. My second choice(s) (if size and weight are a concern) would be a Bravo Gunny or Aurora LT. My next choice would be a Battlehorse Bushcrafter or Essiac (or one of the similar models made by LT Wright) in Full Flat Grind.
If these knives are out of your price range, then try a TOPS BOB (a bit heavy but absolutely bulletproof and way cheaper than the Bravos.) If this is too heavy, an Esee 3 or 4 (uncoated stonewashed blade version) would also serve you quite well, but I hate choils and find their handles to be too short. Another good choice would a stripped BK 16 - although I would be a little concerned that the 16 could be destroyed doing things that a Bravo or BOB would simply yawn at. (Don't get me wrong - the 16 is an excellent all purpose camp and trail knife and will handle any reasonable task asked of it with ease - but if you are one of these guys who is really rough on knives, the Bravo or BOB will take much more abuse imo.) The BK-16 has one of the best handle designs and overall ergonomics of any knife I've ever used. When stripped and reprofiled at 17 degrees, they can be made scary sharp.
I've heard much discussion of scandi ground blades and after a bunch of experimentation, have decided that I hate 'em for general purpose knives. One area in which they truly excel, however, is working with wood. For that reason, I'd also suggest buying a Mora for those times in which you might want to do that sort of thing and put it in your fiance's pack. That way she has a knife if you get separated and you have a back-up blade if you lose your primary. (For that matter, since they only weigh a few ounces and cost practically nothing, you should probably have one in your pack as well.)
A lightweight saw will make your life much simpler as well. A Silky Pocketboy or a Svensaw is worth it's weight in gold when playing in the woods.