Sounds like you found an answer to this question! If you need further help, feel free to reach out to me, I work for Prevost and can help with part numbers.
What did you decide on the couplers? If you need help feel free to reach out to me, I work for Prevost and can help you specifically with the couplers you would need. The Prevost high flow couplers should be fine for your HVLP, standard couplers should be fine for your orbital sanders. You can...