hi, im new so what roomster to buy?

hi, i want to replace my old honda jazz with a roomster as i could get my cycles in the back without having to take the front wheels off. mostly do short journeys so petrol engine maybe best? im unsure about cam chain versus cam belts. i would need a roof rack eventually & nearly all roomsters seem to be lacking the rails but i can't find the templates to buy IF i find a roomster without rails. sorry if ive put too much in one post but its my very first go!

brungo in dorset.