Ignoring the terminology debate, what is the rear fork/dropout spacing on your frame? Shimano Nexus hubs are designed for 130 mm rear spacing and, according to Sheldon Brown, deleting the roller brake will allow them to fit 126 mm spacing. If your frame is 120 mm, cold setting will be needed to one of the wider spacings. Horizontal dropouts, no matter which way they face, are a great benefit.
Here is Sheldon's web page describing the Nexus 7 and 8-speed hub installation procedures:
http://www.sheldonbrown.com/nexus-mech.html