You may also consider the National Semiconductors, they have some nice ICs
One of them is the LM3404 and another one is the LM2734.
More information is on the following pdf file I Uploaded. The file is also available from The web of National but in case you don't want to search for it, it is here:
http://rapidshare.com/files/88632588/lighting_solutions_NSC.pdf
LM2734 is very small in size but LM3404 can supply constant current rather than constant voltage which is better in LED applications of this kind.
I have tryied the LM2734 and works fine. I tryied it with various coils self made and it performed fine.