Have you considered SlideShowPro? It integrates nicely with Lightroom and simultaneously provides Flash and nonFlash content. I've got an example here
of the combo in action, so view it on a Mac/PC and then on iPad to see what you can accomplish.
Your workflow from Lightroom would then be to export JPEGs up to Director (they provide a free Lightroom plugin) rather than going through Web. Once everything is uploaded, you see the "album" in a browser and can change options like transitions, sizes, watermarks, add music if you wish, or even allow the visitor to download full size JPEGs if you trust the client. It then generates some HTML for you to paste onto a web page. You'd provide an individual url to the client and they would see a Flash gallery or HTML if they're using a Flash-crippled device. There are other routes to use SlideShowPro.
You could go for their Director solution where they host your images (no limits on quantity or bandwidth) and then display them using the SlideshowPro Flash gallery. So it's Director (hosted) and SlideshowPro Standalone you'd have to buy.
So much though depends on the tech skills and budget you have available.