Anything free or offtheshelf will have tons of overhead and in-efficient code. Get it the application written by someone that knows what they're doing and you'll be worlds ahead and much happier in the end.

BTW - welcome to WebmasterWorld!

What do you mean by a product selector? After you click on a product to "select" it, what can happen?

Tough one to answer since we are only just starting our research and so I have not found the on-line example that exactly replicates what we want to do.

Many of our products contain the same list of components, but in different proportions. And the products have multiple aliases.

Welcome aboard jerzgirl, almost the exact same question here [webmasterworld.com]. This will most likely require custom programming as discussed in that thread.

I had a similar situation a while back. We went to one of those 'rent a coder' type sites and ended up outsourcing it to the Ukraine. They did a really nice job.

Of course, the one risk is that the coders could leave a few easter eggs in your code. That is difficult to totally prevent. That is true for overseas or local talent.

OTOH, the cost factor is such that, in many cases, it is worth the risk.

One thing about contracting offshore is that there may be some language issues. However these were surprisingly minor.

thanks for your responses and advice. I've got some more thinking and inside investigation to do before giving up on the dream that this app already exists somewhere.