Hi hata,
I too was previously using the Siemens managed 4G93. Found that it was too much of a hassle especially if you're planning on getting more power from the engine. After doing the conversion, everything seems to be going fine.
Here are the list of items that you would need to convert the ECU over to an MMC.
Look for these items from a SGTi year 2000 or below.
GTi MMC ECU #2468, wiring, MAF sensor
GTi MMC throttle body
GTi MMC knock sensor
1.8 GTI Intake Manifold
4G93 Plug Cable
Complete Ignition coil for 4G92 / 4G93
crank angle sensor
There is one more item missing...crank pulley if not mistaken. The original one can still be used but there is no timing marker only, so cannot adjust engine timing.
All in all, the items above will cost around RM1.5k or more, not including installation.
Hope this helps. Good luck.
Cheers...