[MENTION=6682960]Grogg of the North[/MENTION]: that's like bracers of armor++, right? so no further enhancements beyond the +8 AC.
[MENTION=43273]Thurbane[/MENTION]: I think you are referring to "Halfweight" armor.
As far as I can tell, it reduces the weight of the armor, and all armor with this enhancement is treated as light (so no mithral necessary).
Sadly, I don't think my DM will go for it.
It requires to be build by a psionic creature (which don't exist in the campaign) and is from a world-specific sourcebook (which is a problem in itself with this DM)
But thanks for the suggestions!