Update:
Water temperature is normal, needle is staying in the middle of the gauge
Oil temperature, the needle is just under the middle of the gauge
Car is running fine so far
One thing to note is that the last place I took the car to (the one that did the diagnostics), they put the 3 old coils (which I had saved) back into cylinders 5,6 and 8, and it turns out they were fine
So the first garage who tested the coils and told me coils 5,6 and 8 were faulty (due to misfire codes for 5,6 and 8), wasn't exactly being honest with me