A linear transformer (conventional or toroid) based P/S is the most rugged and inexpensive type to use/construct. A complete design analysis is found here:
As you go to single phase switchers or 3 phase inverters, you go up in degrees of complexity as well as cost as well as difficulty to construct and/or tune.
If Bridgeport could make a CNC mill (Eztrak) that drove 3 BIG servos and do so reliably and affordably with a transformer based P/S, it would hardly seem wise to go to the trouble of using a switcher for a DIY effort - UNLESS you can get a switcher dirt cheap and can be assured it has the "oomph" needed to do what you want it to do.
If I were building, I'd go linear - better cost vs benefit vs performance compromise.
Edit - MUCH more robust, too.....