I did not need an uprated oil pump. Truth with that is that there is no such thing for a CVH anymore
There are indeed high pressure pumps but these are pointless as all they do is raise the pressure of the release valve. I have a new Ford pump and a 19 row oil cooler, which is fairly big and I have no pressure problems at all. What is needed is a high flow pump. Burton used to do these many years ago but good luck finding one.
It is connected by fitting a new sandwich plate at the back of the engine which has the take- offs for the oil cooler hoses. You can use the standard Ford oil cooler too or not, it is up to you, you can also buy a sandwich plate with a thermostat in.
As for a good place to mount it, somewhere where it would direct cold air would be best, but S2's are very limited for space once you add a big intercooler. I personally wouldn't bother fitting an oil cooler to a car unless you do trackdays or events. You will not be on full boost long enough in a car that only stays on the road to warrent fitting one.
I hope this little essay helps.