I have not seen risers that go back only. IMHO, I would avoid this anyway since it would bring the bars straight toward the tank and limit future tank bag options.
Have you considered just changing the handle bars to a set with a greater sweep. Or even just rotating yours toward the rear. (This is free to try it out, just a little time spent loosening and tightening things.)
There are 10 types of people, those who know binary and those who don't.
What I ride now:
2013 Honda GoldWing (The Lady)
2014 V-strom 650 (The Mistress)
Previously: 07 Ultra Classic, 95 Softail, 80 gs450l