WST and TiteGroup are my first pistol choices, but I bought some ETR7 because it was fairly cheap and more importantly, it was available. I'm not married to one powder in 9mm because 4# goes far enough that I don't mind resetting the Dillon if I buy something else the next time. To me, components are more easily stored as assembled ammo so I binge load in quantity and then it might be a year or two before I load that caliber again.
Be careful starting out and load for quality, not quantity. The biggest safety tip I can give is don't get distracted while loading.