The only effcient CPU cooling fan that I know of that has LEDs is the one you mentioned the Thermaltake Smart Fan II with LED Mod.
Most LED fans are designed to be case fans and have low CFM and dBa. I can't seem to find any other LED fans that have decent enought airflow to put on a CPU.
You can try it, but from what I can find, the cooling on most LED fans would not be recommended on for cooling a CPU, I'm sure someone disagrees but this is my personal opinion, I have the Smart Fan II (no LED MOD) and its a great cooler for a 80mm fan with decent dBa levels, so if you go with that one you should be good as far as cooling goes.
I am able to get a decent O/C with the Smart Fan on full, XP 2500 @ 2.3 gigs (11.5x200)
Other then that, I can't seem to find a LED fan with decent cooling.