I just noticed that lunaticpapercraft.blogspot.com is already working on Mindy, so I will cede that project to him since it looks like his version has a better chance of standing upright.
I finished this model today and it makes a great display piece. It turned out even better than I anticipated. The picture above shows the 18" version I made, but I also included a 36" version in the download to ease the construction for some. Sandy is unusually tall in the game and the scale of the model reflects that. The only difficult part I encountered involved attaching the face to the helmet (you may need some super glue for that). When properly supported by her wings, she even stands on her own.
This is an update depicting some of my progress on the Sandy model. My laser printer broke before I could print all of the pieces, so my progress has been delayed. I'm working to finish this soon.
I experimented some with Kimahri's dynamic battle pose, but it had too many overlapping planes. In my working model, he's supposed to be holding a spear. Most of his body works out well, but the fingers and toes could cause a problem. Mindy might be fragile since she's so spindly and she'll need some sort of stand.
Update: I just finished layouts for these models too. I'm driving home tomorrow from UF, so I'll have access to a color printer.
I'm 99% sure these are buildable. I've testbuilt most of Seymour already. I'll post the instructions soon, if you need them. Let me know if I need to correct any mistakes. I included Pepakura PDO files to serve as rudimentary instructions for now. Thanks.
Note: Do not attempt to build the beta models. I will release improved final versions in the near future.