These things are so subjective. Honestly your best bet will be to go to a music shop and try out a bunch of different brands/models. See what you like regardless of price. Once you know more or less what you like tonally, you can start looking for a specific model that fits your budget. Based on the bands you list the obvious first-choice would be a Marshall. Especially with a Les Paul you can really get that classic crunch sound pretty effortlessly. Start narrowing from there. Like something crisper? Try Fender. Want more solid-state action? Maybe you'll like Orange. So on. Then you'll find every manufacturer has models in different price ranges depending on features, power output, combo vs stacks, and on and on. So if you decide you like Marshalls, for example. you can find combos for $600 or so, or keep your eyes out for used deals.
Personally if I were buying an amp for myself right this moment it wouldn't even be a question, I'd fork out for a Boogie Mark V and it would break the bank. But that's because I've been playing long enough to know exactly what I need/like. I've been playing an older Mesa for over a decade and paid $1000 for it at the time, but it's been one of the best purchases I've ever made in my life. But it's all down to taste and playing style.
As for the tone of the Les Paul that sounds right. Don't use the neck pickup like that, that's what the bridge pick-up is for Seriously, the neck pickup sounds awesome for cleaner, mid-neck chords but it just is muddier. That's by design. You can turn the tone all the way up, and scoop your EQ if you have one. But your best bet for power chords on a Les Paul is always the bridge pickup or combo. Attack closer to the bridge than the pickup for a brighter tone too.