Mainsheet

Question: I need to replace my mainsheet. Any recommendations on the best rope? 7mm Polilite? This for a Mk I with 40mm blocks.
Also, I've lost both the end bungs off one of my racks. I've got Mk II aluminium racks. Does anyone know where I can get some replacement bungs?
Answer: Marlow 'Excel Lite' in 8mm costs £ 2.36m through Northampton Sailboats / LDC etc - get a length a little longer than the standard - you can always cut a piece off but you can't do anything with one that's too short.
Mike Lyons