LED Boost converter?

[jmole]

Looking to drive 16 LEDs in series from a 48V supply, so I need a boost converter to get the supply to around 60V. However, I also want very responsive dimming via PWM.

I've been doing some reading online, and found that LED Boost converters aren't really usable with high PWM frequencies: http://www.eetimes.com/document.asp?doc_id=1273256

So I'm now wondering if I should use a boost converter to create the 60V rail, and use a buck converter for the LED driving off the rail. I do realize this will lower the efficiency, but will there be any other side effects as well? I.E., is this no better for fast PWM than just using a LED boost converter?