FS2K4 What to use to design an airfield


I understand TTools, used to setup AI flights, but beyond that, I'm a little confused.
I want to be able to put Scenery (hangers etc), with taxyways, aprons, parking spots and an exclusion, all in the one file (OK, OK, two - scenery and textures), but I'm unsure as to how to go about this.
I've looked at AFCAD, very nice, but I can't see how to get the buildings designed. I presume that EOD would be useful for that? But I then can't see how to get those buildings into the file to use. I've also looked at SceneGenX, which seems to be the 2k4 version of Airport.
Anyone able to point me to the "Idiots Guide - How to design your airfield and what tools to use and how they hang together"?
Thanks.