I'm picking up another 20Gal tank (I think it's 20, the long one.) and I'm not sure how I want to set up/decorate it (that's where you [can] come in!)

I've only ever used heat lamps so I'd like to try something new like heat mats. The limit is $250 (not including the tank, $350 including it.)
I want my ball to be as happy as can be with the best interior that [my] money can buy! =)
It doesn't have to be very fancy; my current ball enjoys his paper towel roll and black T-shirt. Currently using Zoo Med Forest Floor substrate but I can get another kind.

 Thanks a bunch!