Proceed: What motorization?

Question see topic. I am about to decide for the procedure. However, I am not yet sure which engine it should be. My childish heart speaks for the GT, also against the background of the equipment. Especially the front windows heating speaks for it. However, I am more the defensive driver and watch out for economical driving. At the same time I find the possibility of sporty driving very attractive. A real dilemma. Heart against mind. Who doesn’t know it?. Despite a commuter distance of about 45 km a day, dealers do not assume that a diesel would be suitable for me. What are your experiences? From when do you think a diesel is worth it? My dealer assumes that due to the relatively small number of kilometres (15000-yearly) the engine could take long-term damage. Really difficult. In addition, I was not able to drive the GT line with 140 hp yet. I’m not sure how the driving feeling is. Thank you very much.