Other than what BrowserUK has said, you could also consider multiple child frames, each for one product, and just show or hide them base on the product selected.

If most of the controls are shared among products, then BrowserUK's is better; otherwise, it makes more sense to use multiple frames.

It also could be a mixture of those two approaches. Group those products that share most of their controls, and use one frame for them, and share or hide controls; but use a different frame for each group.