Do you have a kit? Those have not been available for a long time. Glenn focused on the 1/3rd scale stuff later on and now it would seem he is just not producing anything anymore other than fabric (thankfully).
I have built a couple of his DR1 cowlings, and many of his detail items. A guy here built the 1/3rd DR1. The build is a little built different than what RCer's are used to, but they are very scale. That being said, I will bet it is a handful on the ground. I have a BUSA 1/4 tripe, and have built 2. Even with the cheats to scale that they did, my DR1 is not easy on the ground. It really likes a headwind to keep it pointing straight. As for engine, The Saito FG 30 would be good, or a 150 glow. I had a 180 in my first tripe. I am using a DLE 35 RE in my current one. I have my engine buried in the fuselage to keep it hidden. I had to box it back to achieve this, as the scale nose is so short. A lot of work, but it looks so much better.

Good luck with the build, Triplanes are a blast!