Which whorl wood should I choose? (elm or cocobolo)

If you are looking at Mongolian Elm or Cocobolo as a whorl wood for an Akha spindle, or even in general, then this describes their differences. Cocobolo is a denser wood, if this and the Elm had the same diameter, the cocobolo would weigh a bit more given its density. That means it will spin a bit faster, putting more weight near the shaft (as well as out along the whorl too).

To compare Spindlewood and Forrester Akha Spindles, the Forresters generally have a wider whorl and are a bit heavier -- so they stand up to use as "semi top whorl" style spindles, which is the way many people use their Akha Spindles. In rough comparison, I'd say the Spindlewoods are more likely to spin faster (small whorl diameters) and teh Forresters are more likely to spin longer (larger whorl diameters, and the one with holes which maximizes weight out near the rim for a longer spin).

Re spinning Camel and Cashmere on these -- either the smaller Spindlewood Akha or the larger Forrester Akha would work. I'd probably use a Forrester on those fibers since it is hooked, so you wouldn't have to use a half-hitch. But I avoid giving myself the occasion to mess up my cashmere in the spinning, so I do what I can to avoid half-hitching it.

(this was a reply sent to a customer inquiry, yesterday)