I'd definitely say KSB, from my experience. Very hardy snake, and very forgiving if husbandry is not 100% perfect, as they can tolerate temperature drops well and are more forgiving of higher temps than a BP. Low humidity requirements. Males are notorious for going off food, but should be able to avoid that somewhat with a female. Size is very manageable, with even the females rarely exceeding 2.5 feet. Prices are typically very reasonable.