I am about 170, 5'7", size 10 shoe.

I'm a decent paddler in my SOT, but that sucker's built for fishing so it's got stability in spades. That said, I don't want a super stable kayak. Beginner to intermediate, somewhere in that range. I don't want my wife to climb in it and get wet immediately, but I don't want something that's going to be boring in a year or 2.

I think the main use is going to be open water and surf, but I also would like it to be decent in rivers and lakes. Most of the stuff near me would be class A rivers with the occasional Class 1 rapid. The other bit is that I'd like enough room to do a long weekend trip in it. I backpack a bit, so am used to packing light.

I am larger so I built a Guillemot L for the same purposes you anticipate. I really like it. I think you are standard Guillemot size (rather than the L or the S). I recommend you build it with a retractable skeg.