Thats a really tough question...
I know Biobizz is a europe based company in the Netherlands which a few organic products which can be used in a hydroponic systems such as top max, bio heaven, root juice but those are just additives & enhances...
Another american brand which springs to mind is Earth Juice which i believe is organic but can not remember if its OMRI certified at present.
As JJ Bones mention aquaponics is an intersting method if you don't mind keeping fish at the same time & a fine balance of an eco system working in harmony which ya never buy nutrients ever again, well maybe iron / calcium tho.
From what i've read about it, its fine for veg & keeping mother plants with plenty of nutrients supplyed by the fish waste from bacteria break down with the plants use the nutrients from the process cleansing the water making it suitable for fish to live in safely.
Unfortunaly its not so good for budding as the nutrients created by fish waste lacks a majority of the good stuff needed for big colas of bud, yes it will produce bud !
But not the donkey do da dangly bits sized stuff
Most of the aquaponic systems work on a perpetual ebb & flood system which is quite interesting its about 50% ebb 'n' flood & 50% DWC i'm not gonna go into the mechanics of it tho... but its really cool system
The other methods used is a DWC method known as a styrofoam raft system floating on tanks of water with massive commercial scale lettuce operations are done like this.
Could even do a NFT system like this but strongly suggest against using rockwool with fish as the particals may effect the gills of the fish.