Good Mac Setup for After Effects?

The best system for the money always changes. It is a constantly moving target. More often than not the best performance for the initial cost of ownership in the last few years has usually been on the PC side, but in my business, for everything that I do, when you throw in maintenance, IT costs, protection from virus and malware costs, and resale value my Mac's have been far cheaper to own, operate and upgrade than the Windows machines I have owned. Only you can make that determination. Windows machines are more susceptible to IT problems and configuration and driver issues because the combination of hardware is almost unlimited. I once had Alienware build a customized PC for me that cost nearly 3 times what the Mac Pro I was using cost (a few years ago) and in the first year I had several weeks of downtime trying to figure out drivers and 12 months after purchase the power supply actually blew up with a bang killing the CPU and a bunch of other hardware. It was out of warranty so the repair costs, which were several thousand dollars, was all on me. Instead of fixing it, I sent it to the recycler. Three years later, when the Mac Pro had some memory and processor issues caused by a very tired power supply, I sent it back to Apple - out of warranty and way past Apple Care protection.  Two weeks later and for less than $200 it was back in the office. The price was so low because Apple did not charge me for new memory, or a new CPU and they discounted the price of the power supply. I kept it in service for another couple of years as a rendering node. I've never seen a company that sells or services a PC match Apple Care. This does not mean I have a love affair with Apple, it just means that for me, a guy that has both Windows Machines and Apple products, the cost of ownership and the productivity I have with all of my work has been lower for the Apple products than the PCs. Depending on your workflow, it may be different for you. My only point is that you can't just look at the cost of the machine, you have to look at the cost of doing business.