Not sure if flexwatt will heat the bottom of the cage as I know nothing about Sentec cages. I would probably just go with a RHP personally in that cage.
And thanks. Those are my T10s. I just ordered a stand for them as right now they are too tall for me too lol. I have to use a chair to clean out the top cage. The stand is 8" tall so it will drop the cages down quite a bit. Tall enough so I'm not laying on the floor to clean the bottom cage but low enough I can clean the top cage without a chair haha.