The FAMO track is larger than the SdKfz 7, isn't it? I thought they were two different vehicles?
I found it! The FAMO was the SdKfz 9, with a load capacity of 18 tons. The SdKfz 7 had a load capacity of 8.6 tons!
The FAMO kit is going to be rather more expensive than the SdKfz 7. It's a more detailed kit, and a bigger vehicle.
Check this out, Nick:
1/35 German 18 Ton Heavy Half-Track Famo and Tank Transporter Sd.Ah.116