RE: 1/6'th scale tanks
As Mike mentions, RCTankCombat.com is a good site to check out if your interested in building 1:6 scale tanks on a budget. I've built two to date, a T34-85 and a Cromwell, both to 1:6 scale. I need to correct a statement Mike made regarding the 36" length requirement. Our rules state that if you build at a scale other than 1:6 scale the vehicle hull length must be at least 36". If you build at 1:6 scale the vehicle length can be below 36". We call this our three foot rule. This allows conversion of the 1:6 scale GI Joe toys and also allows construction of the larger tanks to a size that is easily manageable.
Steve T.