Keep in mind that traction is the limitation in lower gears, not the hp.
However, with these cars, more seems to always be better
. 20%-25% is
a reasonable benchmark for hp loss from crank to rear wheels. What you
plan on doing with the car - cruising or tracking - also is a determiner.
Now it is up to you! Have fun. As far as rpms go, that depends on your rear
end ratio. If you will be cruising then the 5 speed with the od will help that.
A little research for YOUR specific needs will give you those answers.