I think the setup would be the same as the Iron Barrel engines use.
Any filter or cooler setup that works for them should work for an AVL as you will have to divert the oil from the external oil tube to the filter and then from the filter to the cylinder head.
Doing a search for "filter" and limiting it to the Iron Barrel section might give you some good information.
As for cooling, the AVL is using a sleeved aluminum cylinder and a heavily finned cylinder head.
The engine was designed for use in India and their temperatures get very close to the same as the temperatures in Phoenix, Arizona. (Just something to think about.)