Andrew is right, perhaps the perspective of that shot wasn't the best choice, sorry.. I was a bit pressed for time when I posted it, but maybe this shot will do the comparison more justice...the last picture of the t-34 and panzer iv is a bit deceptive. I know Ostketten isn't trying to be tricky, it's just the nature of photographs.
As for where to buy...?? There's always ebay, and you can often get good deals from both individuals, and ebay stores if you are patient and know what you want. A few webstores that I have personally used with good results are...
RC Command: http://rccommand.com/
Raidentech: http://www.raidentech.com/rctank.html
Mato Toys: http://www.matotoys.com/canada/index.ph ... f511e1d1bd
I can highly recommend RC Command, excellent prices and top notch customer service. Mato of Canada tends to be a bit pricey and the shipping from Canada is steep but all of Mato's tanks come with metal drive gears, and some are now including metal tracks and sprockets as well. Whether you need metal is a personal choice, many of the pusists insist on it, but I think it depends in large part how hard you plan to run your tanks and on what kind of terrain, if all you're ever gonna do is run it on your driveway I think metal is an uneccasary expense. Hope that helps.