I have a unique part I'm working on that I've modeled as a swept helix.  However, now that I've done that, I no longer have a planar surface to be able to add hole features nor can I mate the part to locate it in my assembly.  I'm intending for the fabricator to build this part by cutting it from a piece of flat plate, machining all the holes, and then pulling it apart to generate the helical shape.  Is there a way I can either:

1) create a series of holes that are planar to the part's surface?

2) create this part as a flat part and then "pull it" apart to get the helix effect ?  The part is 27 " in diameter and 2 inches wide  x 1/4 inch thick