I think if I wanted a 1/4 scale WW1 for that motor, I think I would go with the Neiuport 28.. The Neiuport models are the slightly smaller planes of the WW1 types. However the N11, and N17 have the very small bottom wing. The N28 has more square wing surface inches... I am not certain.. but I THINK the DR1 will work with a 26 if built light?
I do have a friend with a 1/4 BUSA N28. He has a converted 25 cc motor and it flies ok.. The G26 has more power then the converted 25cc motors do.