Much of your decision needs to be based on the time of the year you plan on fishing.

By the end of June the Firehole, Gibbon and Madison rivers (In YNP)are usually much too warm to fish until sometime in the fall again.

The Yellowstone river does not open in the park until July 15th. I heard as of right now the river is not fishing very well. The Cutthroat numbers seem to be in serious decline.

The Henrys fork can be iffy by early July. By then the water gets so warm the the hatches tend to peter out.

The Madison below Hebgen lake usually fishes well all season.

The Gallatin River usually gets good by early July.

If you have the option I would plan a trip for mid June, or wait until late September

Rob