Hi, could you use a cricut mat? I use them all the time in my craft cutter (a Klic-N-Kut--basically a vinyl cutter geared towards crafting). I've even resprayed them with krylon easy tack spray when they lose their stickiness. You can sometimes get these for 50% off at Michaels or Joanns with coupons--depending on the individual store they may or may not accept the coupons for these mats. I cut cardstock all the time with this. Others use quilting mats and even those thin flexible vegetable cutting mats. Just spray with the easy tack (shake can really well, spray outside, and let dry for a few hours. If too sticky, you can blot it with a clean t-shirt to add a little lint)
As far as converting GSDs, it's not super easy because it's a proprietary format. Many download the robomaster program (it's free), open the files, ungroup, thicken lines and convert to black color. Do a print screen, open that image into Paint. Fill with black, copy these objects into your cutter's software and then trace it. Also, a crafter has made a conversion utility:
GSD Conversion. A few other utilities are out there too. Just do a search. Why not try it for cardstock? I use a 60 degree blade for cardstock. Wish I could tell you more about files. What formats are native for the GX24 or the sticka? There are a lot of wpc and ai files out there for crafting could you use those? Just do a search.
HTH,
Kaylene