Well, I've got one up and running using Iframes, and haven't ha\d any problems so far in IE6, NN6 or MFF1, so it seems ok..... only I now have to load up 2 images per link, (front and side view!).
As for the form, I thought it would be easier for it to be filled in as the links where clicked......that way nothing has to be parsed, checked etc.... they just choose the cane, then click proceed, and all the details are their waiting... (may even add a second image set so that the cane is built from the form options, so they can make sure it is all ok!