I am planning to get a turbo for my BA, right now i am just sourcing for parts.

Currently i have the ''97 KF-DE that i need to rebuild (cyl 6 has 8 bar compression) so now i have two options and i cannot decide which would be the best one. I know there are a lot of experienced guys on this forum

Option 1.
Rebuild the KF, but parts are pretty hard to find, specially forged rods. I cannot find forged rods for this engine only custom made which would be expensive since i have to buy in bulk.

Option 2.
Buy a KL and rebuild. Found one for 400 euros. Parts for this one are easier to find, i could find forged rods for a decent price.

Now,
What parts can i reuse for the KL?
I believe the gearbox is the same or at least fits without any adapting flanges.
Driveshafts still plug and play?
What about ECU and wiring? Plan to buy a stand alone ECU and custom wiring but untill than i want to know if i can run the engine on KF ecu and wiring.
My target HP would be 250-300. Can the gearbox and driveshafts handle that?