I have used TL494 in one of the DC to DC convertor though input and output was quite different than yours.

This chip is a SMPS controller with externally RC oscilation alongwith run-time error detection and correction through output feedback driven integerated comparators. We also have possibility to control the flow of current not just voltage. Lately TL494 is widely used in PC power supply designs. I found it quite reliable. Its an Ti chip as you can imagine from TL prefix.

Rauf