I have a tap for a Hoff-Stevens keg you can have for the cost of postage, if you would still be interested.
The design is not like a Sanke. There is no spear. The liquid tube is plastic with a stainless end.
The kegs themselves are very easy to clean. You do have to remove the bung. To do so, make sure all the pressure is released. To release the pressure, insert the tap in the fitting. The is a pressure release valve built into the tap. Just pull on it with some pliers, until there is no more hissing. You can also remove the back flow valve from the gas side of the fitting.
Once you are certain there is no pressure in the keg, you can remove the bung. The easiest way is to get a very large screw driver and punch it through the plastic bung. You can then pry the bung out of the keg.
Drian all the liquid out through the bung hole. Rinse the keg and then you can fill it up with warm water and Oxycleam/PBW. Let it soak overnight. Drain and rinse. You can sanitize with Star-san.
You can find a drilled rubber stopper, similar to what is used in a glass carboy. Put an airlock in it and you will have a 7.75 gallon stainless steel fermenter. Keep it on it's side with the bung hole up. You can use some wooden chocks to make sure it doesn't roll.