LILCBRA you running a bigger diameter tire, then the 3.55 is okay. Enzio has a smaller diameter tire than you (but bigger than stock), but the T5Z with 2.95 first gear, then the 3.55 is also okay. Most of the other T5s (including the V6) have a 3.35 first gear.
Another thing is you are running both upgraded engines and can turn them over 6000RPM and both cars have or will have a limited slip diff.
The rear gear ratio depends IMO strongly on the powerband of the engine, tire diameter, first gear ratio and if diff is limited slip or not. A stock 289 which shifts with stock C4 at around 5000 RPM would not love to have to much rear gear.
I would do it like that: T5 swap, engine upgrades, rear end upgrades. And I learned the hard way on this car: the bottleneck for the engine is the exhaust (because of the tight space in the firewall area and at the rear axle), which will limit RPM level the most.
The best bang for the buck setup without exhaust clearance issues on the MII with a 289/302 is the rotsun setup from roadkill: