The thing is: what if customers want to maintain the website themselves. In FW we can make an iFrame to an external shop, since the topic discussed in the thread above is not a client’s friendly solution.
An external webshop maybe neither but what advise you guys can give in regards to a nice, easy, simple shop (it is not going to be a commercial big thing for this client) that has some options to change it’s colours/interface a bit.