I know of Subaru Gears. Good kit from what I’ve seen online.
If you’re going with the Subaru Gears you shouldn’t need a different bellhousing, just use the Subaru factory flywheel and clutch
You may have a dual mass flywheel on that Legacy. Hunt around for a Gen1 or Gen2 solid mass flywheel. It should be maybe $50 second hand and will bolt straight in.
Cheers
Bennie