Which bike should I buy

Maile bike chalauna suru gareko 2016 bata ra mero first bike was Suzuki Hayate 110 which was of my father, 2018 ma switched to FZ-S V2 single disk and I was quite satisfied until 2023 tara dherai problem aayesi I sold that bike in 2024 and I am currently riding my father’s Hartford Leopard 223.

The problem is my height is 6 feet and the hight of current bike which I am using is short and it is giving me lots of back pain. Also, after riding this bike, I had two accidents in span of 2 months due to braking issue. And spare parts are also hard to find. Beside that, milage is almost 20/liter which is very low.

So, I need suggestion which bike will be best for me regarding my height and having all the safety features and have good milage (35-40kmpl preferred).