The Speed Triple lights mount on a frame to the headstem and don't turn with the bars. That's why they need to stick out a mile.
Because the ZR-7 frame is steel and not alloy it should be relatively easy to have some appropriate nuts welded in place on the headstem, so a complete Speed Triple assembly could bolt right on. I think splicing the wiring to accept a 2nd globe connector wouldn't be to difficult, and I'm sure an auto electrician could do it cheaply.
I still prefer the retro look of the 7inch light. I have a pair of neat Cibie bi-Oscar driving lights lying around and I was gonna install the unit into the ZR-7 shell for winter.
The Cibie bi-oscar is a rally driving light that has hi/lo beam in the one unit. It is very like a Lotus Super7 car headlamp.
I am going to remove the inner lens/reflector unit and install it ( if possible ) in the ZR-7 housing. The Cibie is mucho powerful and gives a really good spread. It will also handle the heat from a 90/100watt globe if you want. Most of my running is freeway so the charging system should handle it.
Both are 7inch but the Cibie runs different connections, so it should slot right in but be a nightmare to wire up.