Since I'm from the wrong side of the
country no I don't know a special needs
computer store in your area.
I do know of a website
www.for-the-people.com
which is run by a blind woman for blind
people. Not sure if anyone on there is
from the San Francisco area but if they
are they would surely know of one. If you
can get your friend to help you out it's a
very easy site to use and uses live voice
over IP chat.
If none of that works let me know I build
computers on the side and if you could
describe what you need I am sure I could
build you one that would work, I would
even be willing to pre-install software
for you.
I hope you can find what you need in your
area though it is much better to work with
local people who will always be there when
you need assistance.