Hello MorallyBankrupt. For a "total noob" you sure have good taste! The M600 has been one of our favorite copters to fly since the first time we put one in the air. Its very stable, flies great, carries heavy cameras or the lighter DJI X5 / X5R and others. The A3 performs vey, very well.
To add to the answer above, it is possible to buy just an A3 and install it into another frame - you can also purchase an A3 with LB2 and use it as your flight control system, radio and video downlink (installed on a different kit). People have been building customs rigs and kits like this for a very long time. If you are a DIY type person you may enjoy this - but many find the complete system of an M600 appealing with no real assembly required.
If can can tell us a little more about your flying experience and your what you will be using the drone for we can certainly talk you through the advantages and disadvantages of purchasing an M600 / M600 Pro or building your own system (either from scratch or a kit).
We also have a client that was looking to sell one if your motivation to build it was to save cost. We would be happy to see if it is still available if you are interested.
Welcome to Inspire Pilots and let us know if we can do anything further to help you.
Thanks!