Purchase advice Leon ST 2.0 TDI

Hello, I’m looking for a Leon ST FL with at least 150 hp and preferably FR and automatic. Since I drive 10-15tkm per year, a diesel is considered. In addition, I also appreciate that a diesel will last longer. Or am I wrong? Are there big differences between the 150 and 184 hp versions (carriage, transmission, etc)? Is the engine the same and the difference exists only in the engine control? This could possibly be changed by chip tuning or is the thought too simple? I’ve already read a lot negative about the automatic transmission in Leon but don’t know which one is installed here. Is this recommended in the 2.0 TDI?