Define your question a little more. What would you like to do with it? It's not that you get one and then you can do everything you want with it. You have to learn a lot of stuff to be able to use it. Some basic stuff can be made easy but there's still a lot to it. What has you interested in one?
You'll just need something in the smaller scale. I built my own but if I were doing it today I'd just get one of these kits from Ahren at cncrouterparts Kit Here For designing grips as well as a large support group along the way pick up Vectric Aspire 4.0 from Ahren as well when you get the kit. I'm nothing other than a customer of components from Ahren, but I can say he has promptly responded to any issue I have had and has earned my respect and business.
I jumped on the Kickstarter for the Handibot CNC machine, should have it in December. It is probably a good size for pistol grips.
Most of what I plan is smaller stuff, but they show how you can index it and make larger stuff also. What attracted me was the small size and portability, along with the "app" approach to running it. For simple stuff like making a precise hole there are going to be stand-alone apps that can run from your phone or tablet.