The FLA-100 fits your requirements, although the way the BOM and plans aren't the easiest to follow.
CNC Router Parts LINK
Fine Line Automation LINK
The plans are at FLA, but you would get your electronics and mechanical parts quicker from CNCRP. There are several on here who are building that model, or a variation from it. Even if you don't build that particular model, the linear motion using 1/4" cold rolled steel and linear carriages that CNCRP came up with for 80/20 extrusions is great.
Before using that, the linear motion I saw most used was roller-skate bearings with aluminum or steel angle, such as on Joes 2006 model. Not that there is anything wrong with that, but since I live in a very humid area, I didn't want to use MDF for my build.