new engine

I personally like being "in charge" of the rebuilding rather than buying one "done" or "all new". You can probably get some great deals on local 318s that were done and have some miles on them. Personally I'd rather have a used one that runs well than a never-been-run reman. I would not buy anything from a mass rebuilder.
Otherwise look around - there might even be something in the classifieds here.