ideally 1 ton (12000 BTU) ac is for a room sized 10x10x10. Now the calc of ur room is 5000 sq-ft which is 5 times, u may try the 2 or 2.5 ton ac but make sure outdoor unit is not in direct sun-light and do god insulation of room ... i've no idea of brand prices/performance when it comes to acs bigger than 1.5 ton ...