First let me iterate that this is for a tabletop RPG campaign that I am running for my local group of players. Now with that mentioned on to the topic of my inquisition and discussion.

In the Fallout verse aside from the post-apocalypse armors you the player come across some pre-war armors once issued to the troops of the good ole' USA... but what could the USA have had in the R&D and prototype stages right before the bombs fell and afterwards by the Enclave and shall we shall a defunct lab of the Commonwealth. We saw a few in the most recent Fallout 3 and New Vegas iterations.

In FO3 we saw for Power Armors the unique Medic Prototype, Enclave models, Ashurs Tribal PA and of course the unique Reilly's Rangers Combat Armor and its other colored variants like Security Armor or Tenpennys troops. http://fallout.wikia.com/wiki/Fallout_3_armor_and_clothing%C2%A0

The following two posts I make will for Combat Armors Variants and Power Armor

Combat Armor Variants-

Developed for the support echelons of the USA forces these combat armors when worn grant the wearer a small Skill set bonus. These sets of combat armor were issued to Special Forces and Support Troops

Demolitions + 5 Big Guns & Explosives

Engineer +5 Repair

Mechanic +10 Repair

Medic +5 Medicine

Technician +5 Science

Rifleman +5 Small Guns

Camouflage Scheme

Developed to allow the soldier to better blend in with his surroundings thus making it harder for the enemy to locate them camouflage is a scheme of varying color patterns on the armor from Jungle to Urban. +10 Sneak when immobile.

ARC Armor

Advanced Radiation Combat Armor or ARC Armor was developed for the battlefield where the US infantryman would encounter radiological fallout from the use of Fat Mans or larger nuclear ordinance. The armor appears to be a combination of the Advanced Radiation Suit and standard Combat Armor worn over it. Repair Advanced Radiation Suit, Radiation Suit, and Combat Armor

Power Armor Prototypes

Hammerhead

Limited prototype production model of the pre-war T-45d slated for the Marine Corps.

Hercules

Pre-war prototype that exceeded the previous models +2 Strength bonus up to +6 allowing the soldier to carry heavy weapons like the M3 Browning HMG or other into combat unimpeded.

Brute

Pre-war prototype that had a +3 Strength instead of the earlier +2 seen in the T-45d model.

Power Armor Equipment

Nice, I've always thought they needed more armor variations. This like http://alex-ichim.deviantart.com/art/3-4-5-395278052?q=favby%3AVATROU%2F60296459&qo=91, as well as http://sobaku-chiuchiu.deviantart.com/art/human-enemies-268058852?q=favby%3AVATROU%2F60296459&qo=114, and http://diegogisbertllorens.deviantart.com/art/USMC-Marine-342826982?q=favby%3AVATROU%2F60296459&qo=349 would make excellent medium and heavy variants. For SWAT forces and special units.

Thanks for the reference pics for inspiration... and wait until I start posting some of the PA equipment I've devised including a shield for PA troops on riot patrol both pre and post war variants.