Here's a taster (all these aircraft are AI):



What you choose for AI rather depends on whether your system will run it as the quality of the aircraft will impact the frame rates. I'd recommend trying the better quality AI first and then compromising if your system shudders under the strain!.
I've used Rick Piper's Viscounts and Vanguards (full models) as AI because they are very frame rate friendly. But get them from the members section on this site as other copies of the files may be corrupted. DM does a selection of ready-to-go AI VC10s and all of his models contain a texture converter within the folder which reduces the poly count and turns them into AI models. You don't need panels or sound with any of these, obviously, and put them into separate folders from any flying models you're using. Prefix all the AI a/c folders with 'AI' so you know which is which.
As ferryman says, you can get most of the older props and jets from Cal Classics http://www.calclassic.com/AIAircraft.htm
And Dee Waldron also has a good selection of base models here http://www.htaimodels.com/downloads/dwai/fs_projects/
There are plenty of repaints on Avsim for them. The quality is variable but they are very good on frame rates and give you a good atmosphere (the little blue and white propellor thingys in the pics are Dee Waldron's :roll: ). I've written my own flightplans but there are comprehensive flightplans for this period at Cal Classics and Retro AI, as already mentioned http://www.retroai.org/.
Setting up AI can be a bit of a dark art so if you have no experience you may be better off with the Cal Classics package. I don't use it myself but probably Dan could advise on that.
Hope this helps
Ian










