Dave, I like what I see my man! This will be a fun project for you and for us to watch happen. There can't really be any substitute for being by the airplane you will model and having the chance to see the airframe up close on a daily basis. The best scale models have been based on engineering drawings and more importantly many personal aircraft visits where the naked eye can take in details as well as quality original pictures meant to help get the lines just right and that do not distort the purportions (easier said than done).

There was a G-IV EDF model made of foam that was released in 1999 or 2000 from a German source. As I recall it had about a 72" wing span and was designed for contemporary fans at the time that would deliver about 2 pounds of thrust each and it had a total weight of about 8 pounds, and was bungee launched of course in typical EDF European fashion at the time. I've seen several videos of it flying and it flew wonderfully on modest power when throttled back. The wing is so naturally efficient that it doesn't even need .5 thrust to weight, but for a model with landing gear, at least .5 or .6 would be nice to have. I have a feeling you may want to demonstrate what a nice, clean and efficient G550 could do without the limits of guys worrying about ther licences (aerobatics)

Good luck, and please do it!