Oh, I found some information, but I still don't know the final drive ratios. I also don't have any info on any automatic Metros other than a '97 I4.
From GM website:
1997 Geo Metro
For 1997:
TRANSMISSIONS
5-speed manual 5-speed manual 3-speed
w/ overdrive w/overdrive automatic
(1.0L L4 engine) (1.3L L4 engine) (1.3L L4 engine)
Gear Ratios 1st 3.42 3.58 2.81
2nd 1.89 1.89 1.55
3rd 1.28 1.28 1.00
4th 0.91 0.91 ----
5th 0.76 0.76 ----
Reverse 3.27 3.27 2.30