As with most things concerning self defense there are trade offs involved.
For what it's worth, here's my 2 cents worth:
First, where you carry has a lot to do with speed of presentation. I believe
that an open top holster just behind strong side hip is best location for a
quick presentation.
I know it's controversial, but I also believe the open trigger guard aids
in getting off a quick first shot. The old Chic Gaylord speed scabbard
shown below on the left is a good example.
A hammer is superfluous for getting off a quick first shot. I prefer the
concealed hammer on my 642-1 shown below.
Rubber grips are a little bit sticky, so I believe they are a bit slower than
slicker grips like the Hogue Blue Lavas. Both shown on 642 below. 2nd
and 3rd from left. The standard wood round butt you mentioned would
be just as good as my Hogues.
After you have decided on where (on your body) you will carry, what gun
you will carry, and what holster you will carry it in, next comes a lot of
practice. When I was training students I always suggested at least a
thousand practice presentations. And practice is another subject that
requires a lot more explanation.