Yah, Spongy read the thread.
With oils, do you understand what they do? Seriously, no one can tell you what the best setup is, since every power system is different, road condition, road surface, and most importantly the DRIVER is different.
Drive your car around. Get a variety of oils. Some people run anywhere from 200-500wt oil with any spring combinations. So "Hard" oil is just a matter of comparison. 200wt is harder than 100wt... what wt are you using?
I would get a range from 200-500wt at least, and experiment with each of them.
Oils are made specifically so that the spring action isn't too jumpy and settles down. However, if you have too much oil weight, you might loose traction when hitting a bump. So technically you should tune the oil weight to the surface and track, and then adjust your springs.
General tuning tip: If your car is not steering in enough, and has too much understeer:
-Decrease spring stiffness in the front
-Increase spring stiffness in the rear
The opposite does...the opposite.
So experiment, please. There is no perfect setup, as you need to find your own. You have a good brushless system so I wouldn't be worried about that.
For your tires, I'd suggest getting a tire you can get a lot of so it is consistent. I like ABS because it is cheap and I can make it myself. HPI T drifts are very popular now, but too expensive for me D:
I am a man of few words.