I would think that a local tire dealer could check your tires for flat spots. Keeping in mind that they're going to want to sell you a set, I'd ask to see the evidence.
I would not recommend storing your GTV up on jack stands for any length of time. I have seen many GTV's with obnoxiously high riding heights. I believe this method of storage causes the springs to stretch. If possible, just roll the car a few inches every month or so. If the space is not available (i.e. small garage) then jack her up, rotate the wheels then set her back down.
I wonder if wheel dollies would prevent flat spotting since most of them have a curved shape where the tires rest.
Here are a couple links I found for wheel dollies:
http://www.bargainjims.com/Images/Pr...e=VehicleDolly
http://www.harborfreight.com/cpi/cta...emnumber=32052
http://www.speedwaymotors.com/produc...No=1&redirect=
