Please help need to know

it sounds like you're buying one used... get the specifications for the one that you'd like to buy and that's where you'll start. what might be causing some confusion to you is that the eight-core machines are dual quad-cores, meaning that there are TWO quad-processors.

also, as with any computer, "any video card and ram" won't necessarily work because there are specific requirements for each machine. there are plenty of places to buy third-party RAM and/or the video cards that will work with your machine, meaning that you do NOT have to buy these things from Apple, but you will have to get something that is compatible with your machine.

once you know the model and specifications of your computer, it's very simple to know whether it's the newest model and what components can be used with your machine.

what you should look for is the processor speed and name, the date it was manufactured, and any tech specs that you can find so that you can compare those to the newest models. good luck.