I actually sized up as I am a 32-33 waist. But either 35 or 36 should work for you. I have a pair of 36s I wear and the thighs measure right at 13.5". That combined with the relatively high rise should give you ample room. I would order the 35 and 36 and return the one that doesn't work out. Not sure how slim you are trying to go.
Dude, I have the exact same problem and exact same size thighs. I just bought the 34 cone greasers from the left field website (most recent lot) and they are perfect. Slim but not tight. I hate jeans that are too tight and I have to stretch them to fit. From what I hear, the cone will stretch though if need be. But I am hoping I don't gain and need that to happen.
I'll echo kulata on the design as I think patch pockets, soft natural shoulders, 3 roll 2, and 3.5 lapels is a timeless look.
I will add that it might be good to have long and short sizes. If not, hopefully this is one of the things you can alter in your new "partial MTM" program on your stock offerings.