Kenyan Sand Boa question?

ok so i am trying to persuade my parents to get me a snake and i wondered if a kenyan sand boa would be the best option as they don't get very big, don't need uv lights and are fairly easy to care for. i was wondering if a 24x15x16 inch tank with 4 inches of aspen in it, a heat mat covering half the tank set to 90F, with 2 hides and a water bowl would be a good setup. and do i only have to feed it once a week and how big will it get on average? thanks