I like the metal lathe, but I'm probably biased... it's all I have (For now).
What kind of parts, and for what kind of two stroke?
A lathe can make pretty much all of your round parts. Your rectangular/square type parts will probably need a mill.
A 7x or 8x lathe could probably handle a lot of round stuff for a small motorcycle type engine. But it may not have the capacity for a larger model. (Think YZ80, not YZ250...)
But, if you were thinking like model airplane/RC car engines you are probably set!