Stupidly, I decided to put on my Zealot suit first, which was probably a bad idea because it sort of ruined a moment I expected to be emotional, getting the new suit. 
 
So, if I ever want to get a new suit for the inventory capacity and that, will I TOTALLY lose the Zealot suit? Or will it re-appear in the store? Or is there some sub-menu for changing suits that I can't find? A bit stressed here!

When you unlock a new suit, you get the upgraded armor and inventory capacity on all of your purchased suits.  They move into your vault, and you can re-equip them from there.  Some suits give you bonuses, so it makes sense to switch to one that suits your playing style, even if you have technically purchased a "better" suit.   
 
For example, I purchased the Vintage armor because it gives 20 inventory slots and 15% armor, but it's bonus is that it gives a discount at stores which I don't find particularly useful.  So I switched back to my security armor, which gives a bonus to pulse rifle damage, but now also has armor and inventory capacity equal to that of the vintage armor.  

i got the hacking suit as a preorder bonus, does it have extra inventory slots?

dose anybody know if you have to find the schematics for the different suits or do you have to buy the next suit in the sequence in order to unlock more suits to buy. I assume you have to find the schematics but I'm pretty far in the game and haven't found any suit schematics. I am able to buy the security suit but I can't remember if I found that or it just appeared in the store.

" dose anybody know if you have to find the schematics for the different suits or do you have to buy the next suit in the sequence in order to unlock more suits to buy. I assume you have to find the schematics but I'm pretty far in the game and haven't found any suit schematics. I am able to buy the security suit but I can't remember if I found that or it just appeared in the store. "

some suits give you 25 slots and 25 % armor. I think that is advanced suit. Riot suit gives you 25 slots and 20% armor. but in my experience, no matter how suit is good, it seems so vulnerable when I go through last chapter (after 13). I don't know. it is always my nightmare even though I finished three times. advanced suit pretty much fuck up in last battle if you don't have enough ammo, and health packs.

" some suits give you 25 slots and 25 % armor. I think that is advanced suit. Riot suit gives you 25 slots and 20% armor. but in my experience, no matter how suit is good, it seems so vulnerable when I go through last chapter (after 13). I don't know. it is always my nightmare even though I finished three times. advanced suit pretty much fuck up in last battle if you don't have enough ammo, and health packs. "