Welcome stratman62, what are the dimensions of the room? A ballpark budget would help. Panasonic/Pioneer for the plasma, Panny's less expensive. The receiver/pre,amp will be determined by your speaker and feature requirements. Are you considering mono- or multi-polar surrounds?
One consideration for the framing, make sure the stud spacing where the plasma and center speaker will be positioned is appropriate. Many in-wall center speakers are wider than what the typical 16" oc stud bay will accommodate.