Welcome to the world of cnc, and all the headaches that are part of the journey! It sounds like you have your ducks in a row for a Newbie. One thing you need to add to your list is your Budget! You can spend a lot on very different approches just to get the same result. For my garage shop, I have an Enco Mill/Drill machine that is converted with 3-axis of Stepper. I have a manual lathe, and am going to purchase another one to convert (just for the heck of it). The Enco (can be seen at useenco.com) is the same one that Harbor Frieght and several others offer. There are others here that can address some of the other sites / machines that are offered as a "turn key" type system. I wanted the Mill/Drill because it is a bit "Beef-ier" and closer to the actual mills on the market. That was a personal choice I made, now I am also in the market for a Bridgeport type mill that I will convert because I am needing the longer travels, and stronger design and higher tollerences that come with this type of machine. But that opens a whole ball of wax, because I am doing this in my garage I need a converter and so on (plus moving the thing around is a pain - I have my lathe and mill on casters so I can move them when cleaning).
You can purchase a Mill/Drill in the $1500-2200 range new. A cheap low end mill in the 3000-8000 range so you can see there is a big difference there. The conversion (with a little creative thinking) can range from <$500 to a reasonable >$800 or so. I am sure you will see some other posts soon that will speak of the other types of cnc machines out there. Take a look at what they all offer, how the individules think of them and what they are using them for. I my case, I can easily cut steels, where some would not fair so well with steels. But then again, you may not want too cut steals, which mean that another approch my be the one you take.
I hope I have helped you out even if only a little. Good luck and please feel free to contact me if I can help in any way I would be happy to. I have been a mechanical engineer for 20+ years, and involved in the cnc (home and at work) for close to that. I have a business that I run out of my garage where I make custom machines and rototics/ automation/pick and place machines. I work 8-5 for the insurance and the money is not bad either.