If you can swing 110 BCD, Sugino XD2 in a 152mm with 24/36/50 rings is about hundred bucks. You can take off the 24 of course, either way use a 107mm BB.

As far as length, it's all subjective. I have a 36" inseam and size 15 feet,. I use to ride 185's. I thought I "had to" ... lol ! Well, I changed to a mid foot pedal position and decided to try shorter cranks. First 175's then 170, nahh. Then the 152 Sugino. Bingo !! Sweet spot !!! I get all the leverage I did with the 185's AND I get a speedy circle to spin. It's indescribably awe-some !!! You won't find this method in book, or an online article, It just arose in me to do it.

36/50 rings are more than enough for especially if you are using an 11t or 12t cog. I'm fine with even a 13t.