Looking for good set of headers and exhaust system for a 400

[73 formulabird 400]

Does anyone have any sugestions for a new system on a formula 400 73? I want full length headers but what size? And which ones will actually fit without (floor and body) problems? And which size primary tubs shouold I get? 1 3/4? Does anyone make stainless steel tubes for the rest of the exhaust system? Any suggestions on mufflers? I need a new system soon, my old original pipes are no good. Last week a downpipe broke of from the manifold and is now VERY loud!! Thanks for any sugestions.