Kirby Lambert was my first thought as well. The quality of his work is fantastic, and he's a great guy to boot. The only issue is that some of his main models (Incinerator, Inferno, Sniper, etc.) have recurves. But some don't, including his wharncliffe and spear-point models.
Incidentally, I have a similarly strong preference for non-recurve blades. I chatted with Kirby quite a bit at SHOT last month, and on one occasion when I mentioned that I love the design, ergos, and size of his larger folders (especially the Incinerator) but prefer non-recurve blades, he said that one of the new models he's working on would likely fit the bill of what I'm interested in. I don't have any more details on it beyond that, but just something to keep an eye out for if you like Kirby's work but none of his current non-recurve models quite fit what you're looking for.
Greg Lightfoot is another excellent suggestion (and, as it happens, another guy I spent quite a bit of time with at the Meyerco booth at SHOT). I have one of his customs -- a Thresher, which is a model he's no longer offering, unfortunately -- and it's a great piece: very comfortable in the hand, super-thick liner lock, well-made, and beautiful finish and choice of materials (CF scales with Silver Twill G-10 bolsters). As with Kirby, your options with Greg are a bit limited as far as non-recurve blade shapes, but he does offer some.