So I pulled out the plans and some small edf units and the rough foam model. If I keep it the same size I can drop in a 51mm Haoye EDF and use the HET 240-14 6000kv motor in it. Should really scream on a good 3s Lipo. Here are a few pics from just kicking around some ideas.
GWS EDF 55 with the HET in it:
Haoye 51mm EDF:
This pic shows the intake template on top of the 51mm EDF unit. Larger than scale but not by much.