That looks like the company I used for my 608 (universal) and 609 certifications, not sure. Never used either license except for the connection at Johnstone, ask them. Being able to buy HVAC stuff through a wholesaler was the payoff for me.

You don't need to buy any study material for 609 certification. Pay for the test and open the study material in one window and the test in another. Look up the answers as you go, open book.

The certifications don't teach you anything that is worth money to anyone. They are licenses to learn.

If you understand superheat, subcool, sensible heat and latent heat of evaporation you know more than most techs.