You might need twin controls as well. One set up for the hot side(s) and one for the cool side(s) as the room is quite cool. The materials and thickness will make massive differences to the set up. I have not used RHPs although I have looked at them. Were you going to keep using the RHPs and supplement with the tape? I think that is what you mean. I use a similar set up with two identical enclosures they use heat tape (cool sides) and UTHs (hot sides) I have a Herpstat pro regulating the temps on both hot and cool sides it has been perfect. My room is also cool 70-75º generally but of chilly nights it will drop to 66º the only thing that changes in the enclosure is the ambient temps from the center of the enclosure they drop sometimes.The hide temps and low level temps are fine.