Sorry, man. I am not a pro with the screen savers. I know that Flash Jester is the best... but it is the most expensive as well. But that's about all I know when it comes to screen savers. Take a look at the programs on the list. I'm sure one of them will do what you're wanting.
Living screen is good. http://www.livingscreen.com
The free demo allows you to build screensavers that expire after 30 days and the full version is around 150 us dollars
the full version allows you to put your own expire date (or none) which is useful if your client wants examples before they buy from you,
you can load more than one swf into the scrnsvr presentation and there's a nice info box that gives customer info when the scrnsvr has been installed http://www.banja.com built their's with living screen check it out