(full disclaimer - they are a long-time wholesale partner making accessories for some devices), but PlanetOfTheVapes is one of the largest reputable brands who actually does testing of new devices before selling them on their website. I know one of the guys who works for them and has a collection of vaporizers that he puts through the ringer and even works directly with manufacturers to help them tweak the designs for better performance or durability.
I'm just a small piece of their business but they are one of the largest and most trusted in the USA.
I will say that while they were a wholesale partner at a previous point, I have heard a lot of negative feedback about CreamCityVapes and how they don't ship orders or wait weeks to ship anything with poor communication. They always paid me on time for inventory so I never had an issue with them, but I have seen far too many complaints over on reddit in the past two years to advise them any longer.
Previously there was another brand called PuffItUp which was a huge brand with a great reputation. But due to the PACT act the owner got scared off and I believe he sold out his business. Now all of his inventory is basically drop-shipped from Greenlane (big distributor in the industry for many brands) and PuffItUp is no longer the brand it was a few years ago.
Let me know if you're in another country and I can tell you some other legitimate businesses I've worked with.