Suspended

The best way of dealing with this would be a box diorama.

Cconsider doing what was done for an IPMS Best of Show from a few years back.

The scene depicts teh crash between a North African Bf-109 and a B-17 where the tail of the Fortress is almost severed (think Memphis Belle scene) The various levels of depth were attached to several layers of glass which are not seen in the dio. Since you'd be dealing with only two layers, rather than verel to hold two aircraft and much debris, you're job would be much easier.

You could also force the perspective by using a 1/48 F-14 and 1/72 F-5. You could even push the effect by just having the nose/canopy of the Tomcat in the foreground attachded to the side wall and the complete F-5 attached to the rear wall by a rod out the fuselage to the back (this rod would be hidden by the fuselage and restricted angle of view). This method would eliminate the need for any layers of glass.

If you're going to be moving this around. I'd avoid any kind of thread as this will allow the models to bounce around and inevitably will cause damage to them.

first i used the monofilament line out of the Revell Magic Flight to hang a c-47 from a case with parachute jumpers leaving the c-47,and worked real well. the line it self can be found at your local magic shop, its called magic string. you might go to e-bay and look at # 5987226230 and check out the magic flight model. good luck!

philip beat me to it, but they are F-5s, and it was supposed to be a MiG-30. Either way, it should be a very interesting dio.

fishing line is the way to go but after you finish the models and the suspension take some low luster paint and squirt the line it'll take the shine off and leave the line a bit less visible

Monofilament fishing line might be a suitable material. It is strong and clear and glues well.

try using very thin but sturdy thread of some sort and attach it to various parts of the plane- wingtips, tail, nose. from upclose you would see it but from afar, it would be too small to see, especially if you use a color that would blend in with the final display area

Have fun.
Actually, the Mig is supposed to be a Mig 30 or 32 or something. Just one of the Top Gun F-5E's in a special paint scheme.
I am actually planning something similar using an A-10 coming off target of 1-2 T-62's. Planned on mounting it by the tail end to the case with a dowel (probably acrylic). You could run this thru the exhaust and then cover it with cotton, etc to hide the supports.