The overdosed clen from research supply didn't kill anyone, just made a few feel close to death.
AG-Guys has been around awhile and generally people say good things about their dosing, BUT their price is more than double most other competitors and damn near triple others. Not worth it for ancillaries.
eds-research is good to go. Bought some clen powder, converted to helios and lets just say I know for a fact its quality powder. If their using the same powder in their liquid products and tabs, they should all be good for a fraction of the price of Ag-Guys.