bulkheads

So I got my secondary account going after the Winking Cat stuff. Got the iCourier and outfitting it with the gained money. Now I noticed something odd. at the station i'm at (tryggvason orbital) there is no stock for bulkheads for the Icourier, but there is stock for the Hauler I used to get out...

Greetings everyone, I'm getting a little issue here I'm on a station looking at Bulkheads while using the option in Odyssey to buy and store, but problem is, what am I buying this for? There is no info appart from price for what ship this hull is for, see by yourself (sorry game is in French but...

I'm planning to upgrade the bulkheads on my Federal Corvette which is now outfitted purely for combat. However, no matter how much I look at the different options I can't decide. I see their attributes and different resistances but I can't quite understand which one would be the best. Obviously...