Burnsco and other marine suppliers do a cast stainless top with a fully welded tube section rod holder. Stainless pin inside, so should last forever...
Reasonably cheap to and very readily available. I would steer clear of ali rod holders personally, but I'm an engineer and I guess I know too much about the failure modes of aluminium...
What I have done (my launch is aluminium) is mount the rod holder on a spreader base with bolts, and then sika and rivet the spreader base down to the hull.
In my case, as the boat is faired and painted it looks mint as and the rod holders can double as tow points for the Bluebridge ferry. The secret is with mounting them is the normal rod holder has the mounting bolts too close to the rodholder tube. There isn't enough meat holding the base to the hull with the size of the rod holder tube...
If you use the spreader base or doubler plate you increase the force required to loosen the rod holder by a factor of ten. The other point is glue it down with Sikaflex 291 as well, as that particular compound sticks poo to clouds.
One you are mounting them, make sure that regardless of the angle of the rodholder to the centerline of the boat the line comes directly off the tip roller and not the side of the rod tip. It can chafe the line... You can adjust the angle of the rod in the holder by repositioning the gimbal pin. There doesn't need to be much hanging onto the pin, there isn't normally much weight on it as it is taken up by the base of the rodholder and the rod butt.