Most of what we do around here could be broken down into just a few paragraphs that can offer an idea of what you can and can't (and should and shouldn't) do to any given Subaru. The questions never change, but the answers are always varied (with incorrect material sometimes delivered like gospel), the information is mucked with filler or flaming, and the Search function get diluted with garbage.
For the OP, I offer the same question as I do every other aspiring major drivetrain modifier: How's your backup car looking?
You can build an engine a million different ways. Some will be close enough. Some will be bulletproof. Some plain and simple will expire, and if that's OK, then you're headed down the right road. If you're building up a daily driver, though, and you don't have a backup machine, aren't familiar with the technology, and especially if you're on the bleeding edge of your budget as it is, you're making a mistake.