Air is plenty. You will need professional design help to be successful.

Thank you - what kind of thermostat do you recommend? Do I have to use a Danfoss thermostat?

Both types of thermostats have their place. If you want to use the radiant heating system as a primary source of heat, then the air is a great option. If this is going to be supplemental heat, use the floor. If you use the air sensing thermostat with another heat source, that other other heat source will keep the radiant heated floor from turning on. This is due to the fact that the other heat source will heat the room up, and the radiant heat floor air thermostat will think the temp is ok and not turn on. So for supplementary heat, go with the floor sensing.

Another great option is to use the floor and air sensing radiant heat thermostats. They sense both floor and air, so it is a best of both worlds scenario.

You do not have to use the Danfoss LX thermostat. There other options that are available, however i prefer and recommend the LX thermostat.