Originally Posted by veganbikes

Do you have the mounting points for either brake? A roller brake is probably going to be a bit better braking but it all depends if you can mount one or the other at this point.

The only time I would use a coaster brake as my main brake on a bike I was building was for a cheap beach cruiser that I was riding at the beach on flat ground where braking isn't really needed so much or if I was building a proper Klunker and was crazy enough to ride it and then I would probably have a proper brake on it because I am not a repack rider, those folks were insane and totally awesome.