Hey mate
At 200,000kms I can't see the ej20y/ ej20x lasting too much longer with decent power (180kw atw plus)
Therefore you're probably up for a rebuild if you decide to keep the car.
Simplest fix - pull the engine out before it lets go so you can salvage some parts.
Then get yourself a brand new ej207 short block with forged pistons from factory - contact kris from rising sun Subaru who will source one for around the $2500 mark I believe.
Reco your standard heads ($600-700)
Buy a set of cams from garage 88 (tomei or jun cams) $1200-1300
Gasket kit - $400
Timing kit $400
Aftermarket single scroll Turbo and factory single scroll exh manifold - $2000
Injectors $50
Fuel rails $700
Fuel pump (buy my sard

) $200
TMIC or fmic kit - $800
Miscellaneous - $500
Labour $2000
Retune $800-1000
Total $12,800 to $13,500 depending on various things and who you know.
Will make 250 kw atw on 98 and circs 280kw atw on e85
To save money you can probably ignore the cams and forego some power and spool up (may mean you need to run a smaller turbo to avoid severe lag)
That's my choice / advice
Good luck
Mick