wall header

I need to remove a 12 foot wall in a office but need to leave the top 4-6 inches. Attached to the top of the header is a drop ceiling supports. data cables, electric wiring. Above the header is 6-8 feet of air before I reach metal trusses. My wall is 2x4, I'm concerned with header bowing even though it's not carring alot of weight. Would 2 2x6's with 1/2" plywood in between be sufficent? I'll have cripple studs at either end.