not a bad idea to replace water pump and thermostat. Timing chain should be in most cases Ok, but don´t take my word for it. What you should look into replacing is most likely not the chain itself but definitely its guides and the tensioner. If the chain is not too expensive replace it too. Probably too obvious to mention are all your gaskets, belts, head bolts and as many seals as you can. Also check your cams for excesive wear.