Answer:

Another project dreamed up during a cold, wet winter not driving:

Two sets of these GSXR 600 K3 throttle bodies:

An spare M20B25 intake manifold

A number of hours with  a hack saw, angle grinder and piller drill on the lathe with a milling bit later:

And you get a nice manifold ready for some ali tubes to be welded on:

The manifold will slot right on being the mounting face of a stock intake as can be seen below:

The nice thing is that the provision for the oil return is already integrated to there's not need to come up with a solution for that:

The stock fuel injection locations will be used, those on the GSXR will be plugged.

The GSXR individual throttles need spacing further out than that standard so some modification will be required to make this work. The K3's have a second set of throttle butterflys controlled by the ECU, these will need removing and the extra holes plugging. The end piece as a TPS integrated. The diameter of the GSXR bodies is 38mm at the engine side, they are tapered and open up a bit more to the intake side. Based on recommendation be other ITB users on E30Zone I picked these over the lager bodies from the GSXR 1000, they are too big for the engine. The 600's should be about right.

The plan is to use tubing to connect the throttles to the manifold so that its possible change the lengths and see what the does to the power!