Buying an AI and designing it?

[Langy]

The information you're looking for is on page 29 of Ultra-Tech:

AI Software: AI software uses the Software Cost Table (p. 25). If bought with extra IQ, Perception, Will, or mental traits (including skills and techniques), each additional character point adds 5% to the cost of the robot. For example, an extra 60 points of modifications adds +300% to the cost. If the cost is negative, don’t reduce the software cost below 20% of the base cost.

In other words, an 'average' AI starts off with zero character points (after paying for its IQ due to complexity and due to the lens you give it).

DX is more difficult. In general, it depends upon the cybershell (the physical body of the robot) rather than the computer. In general, I'd give a generic robot a DX equal to its TL, though that's just a guideline.