http://www.cnczone.com/forums/showthread.php?t=8903 (Inlay artist wants to jump into cnc)
Short answer is check out Rhino (CAD) for drawing at www.rhino3d.com and Rhinocam www.rhinocam.com which has CAM packaged with the CAD for a decent price point. You've mentioned only 2.5d CAM requirements, not any 3d, so you only need basic CAM. There are very low cost options like Sheetcam for 2.5d too. I'm sure others will add some more packages to look at.