It turns out I will need to get a 30v 80w halogen lamp as my transformer will not support the 100w lamp.
When I look for the right lamp you run into a bunch of variations. I'm guessing one needs this from elightbulbs.com
80 watt 30 volt MR16 EPK Projector / Stage / Studio Incandescent Light Bulb
80 watt 30 volt MR16 Bi-Pin (GX5.3) Base 3,400K Clear EKP Reflector Projector / Stage / Studio Halogen Incandescent Ushio Light Bulb
Does anyone know the right lamp.