The question to be resolved first is how serious do you want to get about chasing 'butt?
- Looking just to catch some fish? or
- Looking for an opportunity for a barn door?
- Get on the water as cheap as possible?
- Money no object?
Presuming you're looking at something based in Southcentral (if you want a big-a** butt, go to the Aleutians or Pribilofs), you're options are "sort-of" to chase chicken halibut from six-packs near to shore or to travel 3-4 hours (primarily from Homer) to get further out in the water and have a better chance of big fish.
Set some of those parameters and then it's easier to get to a point of recommending at least a location, if not a specific charter.