It's all done!!
After cleaning up the engine bay, I spent most of Tuesday night putting everything back together. Was a pain in the ass and I scraped the shit out of hands and arms, sooooo many sharp edges along castings and hose clamps.
Unfortunately, she didn't want to start. Then spent the next hour trying to suss out the problem. It was getting fuel but no spark, just turned out to be a blown fuse for the coils. Got that replaced and was up and running.
After installing an oil cooler, it's best to unplug your Crank Angle Sensor and crank the car over a few times to get oil pumped around the engine. Once that's done you just plug the CAS back in and start it up for real, then monitor the oil pressure to make sure it's all within healthy range. Cold idle is about 4-6bar, and once warmed up it should be around 2bar. Warm and under load I was getting anywhere from 3-6bar of oil pressure.
Once everything was warmed up, I made sure the thermo fan controller was setup and working correctly. It was keeping the car cool but the switching points still need to be tweaked a bit. Settings will depend on your radiator and thermostat too.
Then I went out for a quick drive around West End, with no front bar too, and everything was happy =). Got back home and started to drain the oil and replace the cheap oil filter with a decent one. I then flushed out the coolant and put in fresh stuff.