Regarding armor. I downloaded existing mod 4 or 5 days ago and tweaked it according to my feelings, and the result is almost the same as Solarius Scorch described
but i think those weight are a little too high, im using 7 foor dragonskin, 6 for combat armor and 4 for kevlar, and they are still quite cumbersome for rookies, so leaving them without any armor is a viable alternative. I already tweaked the armor values, making them generally weaker than alloy armor and frontal armor always the strongest.
I dont think reaction penalty is a good idea, since x-com soldiers reactions already suck.
I also have some new ideas which im about to test, but i dont have experience in creating new sprite sheets, i cant release new armor without new graphics for public:)
Im going to add:
Assault armor: early game, researchable and manufacturable. Strong frontal armor, weak sides and rear, high weight. I suppose this armor will help keeping your engeneers busy if you play with long research mods, before you start using alien alloys.
Fire-Acid-proof beam-deflecting armor: early game, researchable and manufacturable. Light armor with low armor values, fire immunity, 50-80% acid resistance, 15-40% laser resistance, 10-20% plasma resistance. Or so. Lets you use a lot of incendiaries in close quarters.
Biomechanical suit: based on live muton research and personal armor. Provides a bit less frontal armor, more rear armor, adds some TU, stamina and strength. VERY expensive production.
My idea for psi-armor is that it must isolate psi-activity: lower psi-skill and raise psi-strength, to avoid boosting psi-capable soldiers even further.