When I finally get around to downloading some card models Im looking at the bigger scale as my old hands don't work well with small stuff. Do the model downloads say the scale on them.
Most of the models do state a scale in their description. If you are uncertain as to the actual size base on the scale, you can always send the designer a private message and ask what the finished size will be once it is finished.
Good luck with all of your builds. I forward to seeing your work!