I too am trying to design some cards and I recommend Adobe photoshop and illustrator. They might be a bit pricey but they are worth it for the quality. Another option could be gimp which is free. You can also look into USPCC printing, Legends playing cards which I have heard are cheaper than USPCC and just as good, Expert playing cards which I believe are almost the same as Legends with a few different options and MPC. Good luck with your design!