Is there someone who can help me with mounting my tv on the wall?

i want to run the wires behind the wall and i need power ,hdmi, and coax ..i want to run them all to a 3 gang box that is recessed but im not sure if they have a box for that and if a cover plate is evan possible to find for all 3 ..am i going to have to put in seperate boxes .and if they r out there where would i find them...thanks