Only the FB-111A had the longer-length fuselage. The F-111E was the same length as the F-111A and was distinguishable pretty much only through the later style intakes and the use of three antenna under the nose instead of one larger-style ADF antenna.
The fuselage of the FB-111A (aka F-111G) is the same length as that of the other air force F-111s. This is a common misconception thanks to USAF SAC measuring in the pitot tube in the FB-111A and not measuring it in on TAC Varks (you got to be different!). The big difference between the FB-111A fuselage and the F-111D (which it was based on) is that there is additional fuel tankage in the bomber version. Now there are all sorts of structual differences between different models and batches of the F-111 because it was one of the last paper drawers, iron mongers built planes.
So apart from the wings and colour schemes and carried ordnance the difference for shipbucket is non exsistant. The FB-111A was perhaps the best looking F-111 thanks to SAC painting them in some nice colours. The common scheme was a three colour upper camie job in either green, medium grey and dark grey or light grey, medium grey and dark grey with a lower anti-nuclear flash white.
Looks like a bomber should:
green
grey