there was a guy on here called Boris, the south african dude, that Tom 6"6' and eugein knew, who did a 1.1 mk2 r5 gtt turbo.
i think the easiest was to get around the AEI- flywheel problem is to use the stock R8 distributor, and to modify the swing arms in the base of the unit, so you dont get as much advance as you normally would.
There is also a toothed cam in the r5 1.1 engine dizzy that you can adjust and make the curve more or less aggressive whilst under vacuum conditions (maybe the r8 dizzy is the same).
You obviously wouldnt be able to run any boost retard, but thats why you'd have to be conservative with the swing arm movement
might also be worth looking at H H Ignition solutions too - they are very cheap.
i only say all this because thats basically what the R5 turbo 2 ran. 10deg at idle and 27deg at 3000rpm.