I love the idea of an STi swapped WRX (I'd like to do it to mine some day)
But I agree this is something to approach carefully. It's hard to know what kind of shape the car is in if you can't get the engine to someone who can give you some solid feedback.
Not saying don't go... because this feels like a "full send" moment to me... but be cautious
And also, it's been a few months. Did you pull this trigger or pass?