now I'm confused because if you bought high side drivers, what do you need the TL494 for? High side drivers allow you to switch on NPNs (or N channel FETs) on the source side (high side) by supplying the higher than collector/source (when a FET is turned on, the Drain is essentially at the source level) voltage needed to turn them on... so you can power them with the same voltage that you are switching????
Unless you are looking for a smaller method of generating your DC and want to use a switcher? See AN8209D from onsemi.com.
you don't mention the power you are looking for? 12VDC at what current?
Linear Tech (lineartech.com) lets you input requirements and it tells you what chips you can use and also has a switcher cad program you can download and draw up a switcher circuit and see what happens with different values. You can't get away from the magnetics, but they are a lot smaller. I'm doing an 80W design right now and the transformer is less than an inch tall (1.5 x 1.5 footprint) and light (compared to power transformers) because it's switching at 100KHz, not 60/50Hz.