Simple and quick numbers
Engine gasket kit $300
Bearings $200
Piston rings $250
If you can find good condition Turbo rods and Pistons you'd be up over $500 at minimum, if you go new rods budget $600 if you go pistons at well $800 for factory spec
Need to over haul the factory head with turbo components, so including machining when its off start at $1000 for this, or you could try find a second hand turbo head.
While its apart, oil gears $400, upgrade the timing gear including cam and crank sprockets $1000
Need turbo manifold, turbo, dump, cat and associated lines so another $1000 minimum as you want good condition low km ones.
That is real quick numbers, but you could pick up an fg turbo long motor for $3000.
Hell I got my FG F6 long motor for $3500, there is plenty of those pushing 450kw stock.