I'm guessing you're about to take the plunge? As Jefsview says, we need more info to be able to help in a meaningful fashion.
There are review sections on ECF, but no rating system. So likely wouldn't be of much use until you narrow down what kind of hardware you're interested in, budget, and so on.
But for "openers", I'd recommend picking something that's ego/510 threaded, as that will give the best range of options. Not just in power source, but also in what you put on top of it.
And be prepared to get (at least) two of everything. Backups are important. Unless you own the vape store, in which case you have backups