In reply to Nordie_matt:
What do you know of the structure behind the decorative surface, do you know where the trusses are and were you planning to build off them or build a frame within the room to carry the wall?
Either way, what you're proposing, a very steep panel following the roofline and a big kick panel has a significant strength and a significant weakness. The good thing is you can very effectively vary the apparent steepness by raising or lowering your feet on the kick board. The downside is you will be limited to jugs and pinchy holds on the steep upper wall, moulded slopers will be way too slopey.
I'd consider a panel that hinges from the top and stows against the roof plus a small kick panel hinged to it (there are other good alternatives). Now you can lower the top hinged assembly so it sits on the vertical kick panel which itself sits on the floor giving say a 30deg wall plus 9" kick panel. Alternatively hinge the kick plate up out of the way and the whole thing lowers to the floor giving you a ~20deg wall. The hinge line with multiple hinges adds a lot of stiffness so you can build light. Best bet is draw a section out to scale, sketch in the angles you're interested in then try sketching some options or model it with snapped spaghetti and tape, however your brain works best.
You could build a very good lightweight wall in that space with minimal framing, the key is lots of hinge lines as they add stiffness (think of folded card) and variety. The cleverer/neater it stows away the less trouble you'll be in with your wife too!
jk