Good question Red,
There is a lot that goes into it, and in the end, I don't think there is really one right answer for every application....
I assume you are going with one limb wood and not a core and vineers... because that would be at least three lams.
"sweetness" comes from a few things, among them the number of lams, but more importantly, the wood choosen, tapers, length, width of the limbs and length of the riser... but I digress...
I'd go with four if you can. I'd lay it up like this...
Glass
lam
riser
lam
lam
lam
glass
form
Why three over four? I think there is somehow a smoothness that comes with four, but any more and you begin to loose the KISS principaland have too much possibilities for failure. Any less is fine, I'd take away one of the bottom three lams if you went with three.
Why aren't you going with a taper in there?
Good luck, it won't be the last!
Mike