Focusable parabolic reflectors may not be your first lighting modifier as they are big and require a lot (A LOT) of power, but once you start using them it is pretty hard to go back. To top that, they are also pretty expensive. The medium branded ones are around $800 while a top brand like Broncolor will set you back about $2,400.
If you still want to drive test one of those and at the stage where you have more time than money, Dennis Christian put a tutorial together on building one from scratch (or almost scratch….).