The answer depends. Are you good, or at least have, power tools, like circular saws and drills? Do you have an area you can work in, like a garage? Do you have the time to build one? A cabinet isn't usually something you can build in a weekend or two.
On the other hand, do you have any place you can get a used cabinet from? An arcade, or an amusment machine auction? Or maybe something on eBay or Craigslist that's local? And if you go this route, try to get a generic cabinet. Don't turn a good classic gaming cabinet into a MAME computer.
Read up on various peoples projects to get an idea of what you're getting into (and maybe any features you'd like to have), and I suggest
getting the book.