For adaptive gear, like chest piece
I can easily buy one on the market
But none of them, that I see have an augment slot?
Are they rare.... or can they not get them....

If you can..... how?

Please and thank for any help given

You can add augment slots using an augmentation kit

They are crafted by the way, or buy on GTN.

They can be crafted using Armstech
Grab the gathering skills:
Scavenging and investigation.

Or bought of the GTN.
If you have any other questions please feel free to PM me.

Armormech also makes them. Commando Armormech is one of my main characters, one of your companions gets +5 Armormech Critical (When you crit during crafting you either add an augment slot to gear, or you have a chance to create two of whatever it is you're crafting, augment kits, augments, light saber crystals etc.)
Are the blue items from Investigation? I thought it was Slicing after-all, could be mistaken.

Armstech is investigation.
But you need some sclicing materials to make the old MK-9's