What are the different suit benefits?

There are four different armors available to choose from. It appears that once you make your selection, that you are stuck with that one, so choose wisely. From left to right in your photo:

Wastelander

Allows you to get a discount on all cash items. This does not include vehicle upgrades. The exact discount you receive is 5%.

Roughneck

This offers better protection. I assume this is an armor upgrade of some kind, but don't know an exact % of increased protection you get.

Fabricator

This is described as you build like a pro, and when equipped says the items you build are improved. I don't know of the exact improvement that items you build get, but I would venture a guess that this means turrets and other buildable items might be a bit more durable and last a bit longer than without.

Crimson Elite

This armor is only available to people who have the Anarchy Edition, but it is a combination of all of the above three armors. You get all 3 benefits: 5% cash discounts, increased armor, and better engineering.

If you have the Anarchy Edition, there's no reason not to pick the Crimson Elite, as it gives you the full benefit of the other items.