Hi Firenight,
the Inferno kit won't work, that is the same issue that Bormac had at the beginning of the thread. The mounting positions for the Inferno were completely redesigned.
You just need a universal mount for which you will have to drill two holes, and a cheap battery tray which you can cut to size and mount to the existing holes used to mount the nitro engine.
These are the parts I used.
http://kershawdesigns.com/MotorMounts-1-8-Truggy.html
http://kershawdesigns.com/BatteryTrays.htm
The car you have is the one I have posted in this thread with the green and clear body.
Looking forward to seeing pictures of your build!