While generally on the smaller size of boas because the morph was based in central american lines (which tend to be smaller than their columbian and true red tail cousins) - check out a Blood Boa (Blood is a morph) - that way you get the ease of care of a boa with the coloration of the Dominican Mountain Boas.
here's a link - http://www.cuttingedgeherp.com/bloodboas.html