Let Opel Omega A install gas system !?!?! Need tips and advice

Hello guys, you see my vehicle data below. I plan to have a car gas system installed in the next three months. Could you help me further which gas system is worth it at all? I live in Mönchengladbach, please also call a workshop that is in my vicinity (+- 100 km). I thank you already in advance. Greetings thebozz81