Kevin,
The final drives are all 3.44:1, unless you get VERY lucky.
Porsche Racing made a very few taller sets, but I haven't
been able to find one in two years of trying.
The G50-01(1987) began the original series, which pretty much all had the same ratios. The G50-50(1989) was installed in turbos, has the strongest intenals and case, of all, and has higher ratios than the G50. The G50-52 has the same ratios as the G50-50, without the beefier internals and case.
There are quite a few gearsets available for the G50, here in the USA. Most modifications involve a taller 1st, 4th, and 5th. Unfortunately they aren't cheap! Your best bet, is
to look for a G50-50, and if you can't find a good one, a G50-52.
If you really need the actual gear ratios of the different boxes, I can dig them up. Let me know, via e-mail.
Unless you are planning to race the car, or use a high horsepower engine, stock clutch parts should be fine.
Bill