bangkok hotel, airport and the southern bus terminal?

where is the best and most strategic place to book a hotel in bangkok?
we'll only be spending a day in bkk. we'll be coming from suvarnabhumi airport, book a hotel and take a day tour in bangkok, go to phuket via bus at the southern bus terminal in the evening. is the airport situated near the southern bus terminal?

The Southern Bus Terminal is not near the airport. In fact it's on the other side of the city in Thonburi, Pinklao area.. The new terminal just opened a month or so ago. If you want a place close to the terminal it would be the Royal City Hotel http://www.sawadee.com/hotel/bangkok/royalcity/ it is also not far from the Grand Palace and Wat Po and Khao San Road. Hope this helped you. Have fun.