If you do go for a 1/6 Stuart, particularly on eBay, it's worth making sure that it's the RC version. There's a static model too, and some such sellers, through ignorance or otherwise, don't exactly go out of their way to make that fact clear. Here's a particularly neat Stuart (which apparently uses a turret from the static model).

More at :

http://www.customrcmodels.com/M5Stuart/id87.htm