My humble and somewhat inexperienced opinion, I am a TR3 guy but it is basically the same engine, there are a few options available to you, what you decide to install depends on a few factors such as engine configuration, driving habits and personal preference. I found there were four options; copper wrapped composite, a composite gasket and a solid copper or shim steel used on competition engines which are provided in various bore sizes and thickness. The solid copper, like the steel shim gasket, seems to be used mostly, if not exclusively, by racers with high compression engines and the other more widely used copper and composite are available from the usual suppliers are quite common. I think the composite HG available from Moss is a high quality HG and would be quite durable for most uses and does not require gasket sealant I am told. The copper wrapped composite and solid copper do require sealant and are also good well tested and used options. I think it is important to have a good flat head, good head studs (I replaced mine with the ARP High performance studs) proper piston liner height alignment etc. and to correctly install the HG. If you have a quality installation no matter which option you choose, you should be good to go for a long time!