A friend of mine has the Great Planes Dr-1 triplane ARF with an OS .70 in it. It flies very nicely, but you need to be careful in a cross wind.

Hobby People has a D-7 ARF available that would be nice for a .70FS.

Balsa USA has a .40 size Eindecker kit that I flew with a Saito .72. We took another one and midified it into a Morane-Saulnier Type N. They also have a Bristol M-1 WW I monoplane and a Taube in .40 2-stroke/.70FS size. The giant BUSA Eindecker flies with a .91FS, but you use half power fo you could do it with a .70 if you want to stick to scale speed.

The Hobby Hangar kits would be a little small for the .70, but could be done. We built and flew both kits with a Magnum .52FS and a Magnum .61FS.