Hey about pro fighters?

idk what fighting style i should focus on ive studied a lot all my life.I weight one hundred fifty pounds and im 5'6 im strong,but 3 ppl can hit harder than me i know im fast but 1 person i know can hit faster than me.So i wanna be a pro cage fighter should i try being a muaythai boxer? or a speed boxer?What should i rely on and what fighting styles should i take i already take bjj.What im best at is hitting hard and cardio and submissions but really im just good at everything like gsp.I wanna be a ko spec or a speed fighter what should i try to be to make it pro.I mean ppl like forrest Griffin hes alright at everything but his spec is he can fight without getting ko or sub and wins like that.