The header wrap stuff will work. If you opt to go this route be sure to get some of the aerosol sealer sold for it too. A friend almost lost his car due to an ATF leak that put it in the wrap. Danged hard to put out one of those fires.
Also note that such wraps keep the heat inside the pipe, which can shorten their life from a little to considerably depending on temps and what the tube is made from.
A metal heat shield would be my preference. Can stand it off from either the tube or the floor, which ever is easier. Try to build it so that air flow under the vehicle goes between it and the floor. I use hose clamps when the tube is the mount point of choice. I usually shoot for placing the sheet halfway between the tube and the body. If a bead roller is available rolling a bead around the edge of the sheet helps with rigidity and can sometimes keep it from vibrating and making noise when going down the road.