I've never seen any other in the trade than gigas, specifically the ones supposed / labeled leptosoma grow to the same 6ft + in the same time as do nominal gigas - this is what Wesley Wong tells me and tells us and I 100% believe Wes.
This fish seems pretty light colored, either very stressed in the photo or a morph. If the latter, it'd be worth 10x or more, though I am the opposite of a morph lover.