Awryt . CFA is the best course generally. But when it comes to Qatar, CMA and CPA would be a better choice than CFA as there are not many good opportunities for it. If you want to get into financial accounting jobs, u can go for CPA otherwise CMA for Management accounting jobs. All these courses will take around 2 years to complete.
(To improve yourself, you can go for any of the courses you have mentioned. All are good. But choosing a particular course depends mainly on what kind of job you like/want to do in the future.)