The Calvin Beal boats website lists the draft of the 34' at 3'10". From the measurements I have personally taken of the boat, I would say the real draft is in the 3'6"-3'10" range. My boat was basic and light, so I was probably 3'6" - 3'7". As a side note, the propeller apeture of the 34' Calvin Beal is approx 32.75" - 33"; So a 28" prop will just fit on a 34' Calvin.
The Young Bros website lists the 33' and 35's drafts as 3'2". I have no personal knowledge if that is correct or not, but the owner of the molds, Stewart Workman, could tell you. If the draft on the 33' for example, is truly 3'2", then the biggest prop you could fit under it would likely be a 24" diameter (again, no personal knowledge of the Young Bros, just an educated guess). 24" diam. prop on a light 33' boat is adequate, although I wouldn't want to go any smaller.
I think (not 100% positive) that the 33' Flowers will allow a 30" diameter propeller, which means it's draft will be at least 2" deeper than the 34' Calvin. Some may disagree with me (everyone has an opinion), but a 30" diameter prop on a 33' boat is overkill and not necessary. So if draft is an issue, I would probably steer away from the 33' Flowers.(for some $$$$ Ken Flowers could probably modify the keel and reduce the draft)
I can tell you with much confidence that of the boats available in the 33'-ish range, the 34' Calvin with it's wider beam, will be the most stable on the drift. Although, the 33' Flowers, 33' Crowley Beal, and 32' Mitchell Cove would probably be nice stable boats as well.