Questions about the Vectra 2.8l V6 OPC for purchase

Good day, I’m new here and I’ve already read a lot of posts here. must say I like the way around and the help of the individual users here! now to my questions! I would like to get a vectra c and was so far on a 2liter turbo! now the possibility has come up to get a vectra OPC! 1. which would you recommend more the 2liter or the OPC? 2. how is your consumption in the city and autobahn with nem 280PS OPC? 3. have now in my Jeepgas autogas the OPC is BJ 04/08 is this series ok or is there any faults to consider!? 5. what does it look like with prizes for parts? are they in the frame and I will fall at the cash register! is this the case with my jeep at the moment! had previously Calibra and Corsa and well there the parts were cheap! LOL I say already quite warm thanks for the help and any answer! mfg