It is possible to use the omni studio with monitors. There are dedicated outputs for them on the breakout box. However, that doesn't necessary stop you from having to use a power amp. It cuts out the need for some kind of mixer, mainly to control volume. It you get active monitors (ones that are powered), you wouldn't need anything else, but to plug them into the omni studio. If you get passive monitors, you would still need a power amp to drive them. The omni studio makes it very convenient to monitor everything you're recording. I've had great success with that soundcard for a couple years now.
Brandon