I have done a similar system as the first one. If you go to
www.aprilairecontractor.com and call the tech support they are very good and quick to answer your questions.
From what I remember most floor heat setups are 24v on, which the aprilaire 8870 does. You will need cat5 at the T-stat location OR you can use the flush mount temp sensors on the stat wire and locate the stats at the furnace location with cat5 from there to your eq location.