Not that he will mind too much, but a ksb will never need a 55gal maybe a female will need a 20gal long, but in most cases a 10 gal will do for a long time. Splitting your 33 long would be a great idea!
Heating, I have an uth and keep the temps 105-110 on the glass with a 1/2" or so of sand and a piece of plexi resting on the sand he likes to hide under. There is nothing on the cool side. I prefer sand and could be a big debate but I keep it clean!