I think you could get into it with just an Ant+ speed and cadence sensor paired with an Ant+ USB-m dongle on your Windows 7+ or OS X 10.7+ computer. The heart rate sensor would add a dimension but isn't required. Based on a recommendation I got this Suunto Movestick Mini. Note that Zwift isn't spec'ed to work with Ant1 dongles, which may still be out there for sale. I tried an older and larger Garmin Ant1 stick first and it did not work with Zwift though it did with Golden Cheetah.

If you're motivated, the trainer can help you maintain consistency in riding regardless of weather, allergies, darkness or other conditions outside. Plus you can get more of a workout indoors in a given period. And though you incur some cost if you add some sensors to your trainer riding, you are saving some wear and tear on your bike which means some reduced maintenance and components cost.

A vast number of additional indoor training applications are reviewed in the Winter 2014-2015 Trainer App In-Depth Guide. Some of these would also work with your Kinetic Road Machine.