I think Animal Plastic 48" will be the best Option..
I keep my in same rack with balls an my RBI rack have only 4" tape.. on beging and end of Heating season my room will get as low as 65-70.. I crack Thermostat to 110 and with minimum 1 inch thick layer of substrate I never had problem with burns or snakes getting cold...
My balls like little colder in winter anyway 84-76 and my house snake are per4fectly fine between 80-70

Rack (4 drawer sweater box from RBI is perfect) are nice space saver but i've kept pair of houses in low Exoterras and those are fun to watch...

So go with 48 in AP with Divider