I'd personally go with grabbing some compatible plans for the type of cabinet you want off of a site like Jakobud.com and building the whole thing yourself. It will cost waaaaay less. Cabinet kits, (including the PC, or not) are nice, but, personal opinion here, vastly overpriced regardless of where they're coming from.
It feels more rewarding if you make your own, it's totally custom and has exactly what YOU need in it, nothing more, nothing less.
You can pay 1400 for a MameRoom/NorthCoast Customs machine, that will no doubt be a well built machine, but you can also build ones just as well, for 200-300 (cabinet, and maybe even less than that) and anywhere from 300 to 600 for a PC that will run everything MAME can run plus some extra PC software like Street Fighter 4.
So, 1400, one size fits all, or 900 at the most for a custom job that your hard work went into, Not only will you be able to enjoy using it because of the content on it, you'll also be able to enjoy it even more knowing you worked hard for it. Sort of like when you finally finish rebuilding a classic car and finally get to take it for a drive.
So that's my opinion. However, if you do not have the time, if you are willing to spend the extra cash, if you just want a cab and you wanted sooner than later. Then NorthCoast does make some good systems.
So while you'd save money, and have an additional sense of pride and accomplishment once your project was done, you would not be throwing money away if you went for a NCC cabinet. But shop around if you haven't. There are other cabinets out there. Quasimoto Interactive for example.