I believe you will quickly find out you are dealing with a 1.5/1.8 to 2.10 requirement once you get to 60-62" w/s on the D-17. The massive frontal area and basic flying trash can aspect of the fuselage will quickly eat up any 1.2/1.5 prop size much less a .90. You might want to consider use of a gasoline engine to get the prop and torque you will need.

The Paul Matt drawings will provide a good basis for designing your own. I believe SPPS will possibly have a planset from which you could carve out a great deal of short cuts as well.

Acqusition of a Byron Originals D-17 fuselage will serve the purpose of getting you into a plug even faster. I believe Walker has a gear for the D-17, maybe not in the proper size but that never held him up making the correct size:^)