If you like to program pics, there is one that has been suited to smps. it´s the DSPIC30f2020, if i am not mistake. it has a PWM max period of about 1ns.
i am trying to do one SMPS, based on a simple one like 16F628A, just to test some parameters, but if you have te constraint of having 3 outputs, you must have to have at least 3 independent channels. But if you don´t like to build another projetct into your project, there are some ICs that are suited to it. There are some good articles about microcontroller smps in microchip´s site and also there is a good one there about transformeless power supllies. For the specifics ICs, look for them in Texas and Analog Devices. If you do not have much knowledge in the area, it´s best first to understand a bit about different topologies of smps, it will help you to select the most appropriate component.
Good luck!