I don't have a strippit, but have other brand turrets (Amada and Wiedemann).
You need two pieces of software:
1) Software to draw your parts and specify which tools hit where on the part, and to repeat that shape to fill up a whole sheet of material, and to convert that drawing/hit info into gcode which your machine can understand.
2) Software to transfer the gcode to the machine control (called DNC software).
For the drawing/gcode generation software, there are several expensive packages (starting around $5,000 or so), and one program which costs only a few hundred. It is called gpuncher -
http://www.metalpuncher.com/ . That's what I use, and I reccommend it. Not only is it affordable, but well it works fine (yes it does have some quirks) and there is no way I could justify paying over ten times its cost for another brand of software that does the same thing.
For the DNC software, there are lots of packages out there as this same software is also used for cnc milling machines which are much more plentiful than turret punch presses. Make sure that the software package has the ability to repeatedly send the same file over and over since this is likely how you will be running the machine (running lots of sheets of the same file), wheras I have found most of the DNC software to be more oriented towards sending a file once (and then you'd have to re-select the file on the computer to send it again). I can't reccommend a piece of software in this department as ours is super old and specific to the piece of hardware that it is feeding data to.