I own a few multiblades or slipjoints. (actually may a little more than a few).
I would do the following (the order is not in any hierarchy)
Order one from Tony. (My last one took 5 years.)
Order one from Eugene (My last one took about 2 years.)
Order one from Ryuichi (You should get it within a year.)
Order one from Bill (I am not sure how long it will take, but I have 2 knifes of his that easily compare to anyone's.)
Order one from Joel. (about a year maybe less.) Joel is very creative. He was the first maker I know that figured out how to put a true "capped bolster" on a doctor's knife.
Order one from Richard (Even though I have 6 or 7 of his knives I am not sure how long the wait will be).
Order one from Terry Davis.
Do a little reasearh on Jack Davenport and order one from him.
Order one from C. Gray. Taylor.
Order one from Ron Newton.
Order one from Bailey Bradshaw.
Order one from Reese Bose.
Order one from Dan Burke.
Order one from Barry Davis.
Repeat multiple times.
I really like Ohta's work and plan to order from him or try to get one at Blade next year, but those guys along with a few others (Osborne, Kios, Overeynder, Embretsen) are at the top of the the heap in quality, fit, finish and action. These are very tough knives to make right and believe it or not some of those makers work are at the highest demand of any (except maybe Ken, Don, Kit and Walter) in Custom knives.
Speaking of Kit, I carry a bone lockback that he made at all times. I wonder if I could talk him into a doctor's knife or whittler

(Na I better not even go there.)