Manual choke conversion

[rhughes@domain.elided]

I'm thinking of converting the thermal-controlled choke on my Holley 2210c
over to a manual.  My understanding is that I might be able to improve my
mpg a bit with savvy use of a manual choke.  I looked at a manual choke kit
the other day, however, and now I have some questions:

1.  Are some kits better than others?  What should I look for?

2.  Will the manual choke still need the vacuum choke pull-off?  Does it
hook up the same?

3.  I assume the fast idle cam and linkage work the same, right?

4.  Most importantly, how do you effectively use a manual choke?  Closed on
startup, I guess?  What about a warm startup?
How quickly can you open the choke up?  How do you employ the manual choke
to get mpg gains?