http://www.etoarmor.com
Sevo (Robert) here on the forums would be your best bet. He is located overseas but yellowshaker (Joe) is his east coast distributer. Lots of tamiya parts. Oh and the original Sherman does not have recoil. And to change that you would need to get the Pershing electronics and recoil. Not sure about the Leo being frowned upon, but every club is different. Most people run WWII era tanks.
Cheers
Wade