For the speeds, the x8 multi at 3.20ghz and 50c high? That's excellent.
For the x9 multi at 3.40ghz? That's still acceptable but 58c for the highest is not my cup of tea, I'd say keeping it below 55c should the more acceptable. Even though 68c is supposed to be the highest for the C2D.
Whatever cooling you have right now, I wouldn't change it.
BTW, don't get the FM121, it's noisy as hell and not worth it. I have one right now with my TT120 and I had to set the rpm AT 2k because at 2,400, the fan sounds horribly loud, so, 400 rpm less and it sounds just like the TT120s stock fan and guess what? Same temperatures, no difference at all.
The TT120's stock fan is perfect but if you're willing to withstand all that noise with the FM121 at 2,400rpm, go for it, the only difference in temps were 2c-to 3-c less than the stock TT120's fan but the noise was unbearable for me.