Depends how far you want to go Gav, 19 row oil cooler with -10 pipe work to it is what you need on there if you use it mainly on the road, how far you want top go will determine what parts you need exactly i.e. do you want to keep the oil filter in the std location or mount it remotely, same for oil stat. Also oil type / grade can make a difference, what oil are you using?

I would say yes you definitely do need an oil stat in the system otherwise the oil will take too long to get up to temp when weather is cold or you are just cruising on the motorway.