Roger,
Perhaps you could do several of us a favor, and post the set of standard knobs here. I'm a little confused on this myself... I don't have my bass yet, but I would describe the knobs on my SF-2 as being both 'hat' and 'collet', and was under the impression they are the same as used on instruments, available in both 3/4 and 1/2 inch knob diameters (not clear on shaft sizes).
The other thing I'm a bit curious about is whether you've done much with knob styles that have a 'tactile arrow' - still a round knob (not a pointer or 'chicken head' style), but with an indicator that you can actually feel. I could imagine a slightly protruding inlay up the side, or something like that.
I'm really not anywhere close to thinking about ordering knobs, but at least the idea is floating around in the back of my mind.
Thanks.
-Bob