Well if I were you id simply get a Herp 2 or VE-300 (for 2 probes) that way when you get another rack (with bigger tubs that need thicker tape) you can use, with there heat tape, i think they use the 3" which i belive is 10watts/foot

So even still your only at "500" still 200 watts left, Secondly, you Can use a power bar (simple 1 no need for the 50$ ones) and connect EACH section into the power bar then connect that into your Herp. The only thing is, IF you have a second rack 41qt for bigger girls you'd need 6-12" heat tape. Which needs to be connected to the other outlet, (aslong as the flexxwatt or THG tape is same size/wattage) they can be all ran into power bar then into herpstat.

Good luck with your snakes! I have both Pied/Bumble bee and like you just got my Spied out of them! Gorgeous snakes!