Going to drop iWeb if we can't get automatic slideshow

You mite want to start learning HTML, CSS, and jQuery. You will only become more and more limited by iWeb, that is not designed for professional sites regardless.

Once you have a mastering of basic HTML and CSS then moving onto jQuery will give you all the power you need for interactive slideshows and many other things. jQuery coding is quite trivial and easy to learn though can be difficult to master as most things are.

Wordpress wile good at what it does will pull up the same road blocks as iWeb if you do not know how to get into the nitty gritty to do the things you want.

 

I have to agree with Cabbit here, if you hope to have successful business with a successful website you need to step away from iWeb. HTML and CSS are relatively simple to pick up and with HTML5 and CSS3 giving you more options then ever before.

To answer your query, you're going to need jQuery to get the results you require. If learning the skills you need isn't an option, then get someone in to create something - chances are if iWeb has met most of your needs to this point then a web designer should be able to create/code something for you in a few days.