The best option to try and stop the noise is an ester based 5w-40, expensive, but they are the best oils on the market.
http://www.opieoils.co.uk/c-656-5w-40.aspxOut of those, the ester ones are the Fuchs/Silkolene Pro S, Millers CFS, Motul 300V, Redline and Gulf Competition. Ester oils leave a layer of oil on metal parts (like the Magnatec ads on TV show, but a whole lot better than that). So when you start the car, there is already oil in place. Also a 5w oil will get around quickly from cold, so the oil is doing what it should be as quickly as possible.
It won't be tto thin when the weather warms up, just like a 10w-40, it's a 40 when hot, so the same viscosity. Also, ester oils are very good at absorbing sound, so they should keep the engine nice and quiet.
Cheers
Tim