I am going to get a Kane heat mat. I am deciding whether I should get an 18"/28" or a 13"/48". I think that I should get the former one because heating the legs and main body is more important then the tail, but the problem is, I don't know exactly how wide these guys can get(when sprawled out). Though what I have said is likely true, they do seem to have pretty meaty tails(that need to be kept warm). Which one is better?

