On the picture below I tried to depict most important or most expensive parts that will comprise my design. On the left side you have power supply part which would provide 3 voltages. 7.2V is for the heaters and the stepper motor (now the lab's power supply is making it). It has to be a switching dc/dc converter because heaters can draw enormous amount of current (). 5V is for the head's logic and in current state 5V is supplied by the USB connected to the TIVA evaluation board which then is passed to the head. 3V3 is for the µC.

I included the FFC connector on my diagram, because these things tend to be quite expensive when I checked them on farnell and I wanted to include all most expensive parts on the drawing to get a glimpse of what the final cost may be. The plan is to make this device as cheap as possible to be able to eventually make a product out of it.