Mini Humbuckers offer you the best of both worlds; they are humbucking (i.e. no 60-cycle hum), they are capable of great chime and clarity when you play clean, and when you use a lot of drive, they sound fantiastic. They will never sound quite the same as a full-sized humbucker, but they have a fullness and grit all their own. You really have to experiment and find the ones that are best for you, but it is worth the effort.
Every time I look at a Firebird, I have to laugh. Gibson was so desperate to catch up with Fender back in the early ’60s, they hired a car designer to help them come up with something more hip. Personally, think the guy was on cat-nip. What a nutty looking guitar. But I have always loved it and think it is nothing short of hipster-doofus-genius.