While I haven’t played the reaper at all, I do have experience with a variation on this build. I’ve tanked 2v1 and come out ahead most of the time.
http://gw2skills.net/editor/?vRAQNBhOD7kGRobTsrGwtGg9GsMNYTjgLQFQaAUACAxjwS4LE-TpRBwAWuAAlLDw/IAs4BAA4gAEb/BA