I can't commit just yet, as I have too many going. But the dream project would be one I've been collecting material for.
The M3 Grant based Canal Defence Light. Over 300 of these were converted, plus 300 Matildas.
The turret was replaced with an armored cupola that contained a 13 million candle power search light. There was also a dummy 37 mm gun. The light aperture is the vertical slot just to the side of the turret "gun".
A successful concept, they were used from D-Day Normandy on, and were a key defence against night counter attacks at the Rhine Crossing at Remagen.
I'd use an Academy Grant that I've got salted away somewhere.
I'll be following in any case.