Injectors, fuel-pump, up-pipe, downpipe, larger top-mount intercooler, some sort of tuning for all of said mods, e85 fuel will be necessary to reach 280-300 at the wheels.
And nearly all of that can be obtained in the FS section on here! Tuners would be RS Motors or NF Performance for the most part. Although there are a couple of other options also.
I thought that it was twin scroll! Didn't know that it came out of a Legacy tho. Thanks for the skoolin sweet pea!