Thanks for the replies; those are the sort of things I was looking for. I need to stick with high-side current sensing for my application. I like the idea of just making a single stage flyback converter with a xenon photoflash transformer, but, correct me if I am wrong, wouldn't that have the same problem as a single stage single inductor boost converter of not allowing for very precise adjustments due to errors in duty cycles? Also, all the flyback models I can find only give the output voltage as the input voltage times the ratio of the windings where as with a single inductor boost converter, you simply adjust the duty cycle to adjust output voltage. So am I correct in seeing the flyback converter as only a way to multiply the voltage by a constant set by the ratio of the turns on the transformer?