no way to make it fit in a beetle without seeing the body mods. It has been done many times but you can always tell (maybe someone has done it better but i havent seen that yet) As for the van, It only need some minor trimming to fit in BUT it needs a ton of other work and parts.
not a simple job but not that technical. Just make sure you have ALL the parts that go along with the eng when you buy it, oil tank, ignition, oil lines, clutch etc. If it's going in a bus you can use a adapter flywheel to use the bus trans. If you use the porsche trans you will need to make mounts as well as other parts.