I've always heard Heavy 16 is the brand to go to for this, I've had really good success using their products. I'm not totally sure which option would be best in your case, but my money is on the Veg A&B:
http://www.htgsupply.com/products/heavy-16-veg-ab
Or, this one is their 'standard' option:
http://www.htgsupply.com/products/he...me-concentrate
hope this helps.