I am sticking with the three stock Antec Tri-Cool fans provided and see how it goes, I'm in no rush to spend an extra £20-£30 on top of the case cost. I have used the Antec Tri Cools before and they are decent enough, had them set to low and they are fairly quiet but still do their job.
As far as I know its only the Antec Tri-Cools that come with the little adjuster. If you want to take it to the max then consider buying some powerful fans and hooking them up to a fan controller at the front of the case, otherwise just stick with the Tri-Cools and see how you get on.
Do you have all three fans set to low? If I do that, then the lower fan does not start on startup, it needs Medium to start.
Also, the manual says for better CPU cooling set the two top fans to Low - I would have though High would provide better cooling?