iMac 24's for tradeshow displays?

I'm in the imaging industry and am considering getting a pair of refurbed 24 IMACs to use as interactive displays at our tradeshow booths.

The idea is that there would be a simple screen with 3-5 options that they could click to view a video slideshow. Is there a simple piece of software that I could use for this? Perhaps front row would work in the dvd section? Once finished playing does it go back to the same menu?

Is there another, perhaps more economical, option to do the same thing? I currently use a MBP and external 23 cinema display. (I don't want to run one 24imac and have the cinema display attached. - I want to keep things pretty and symmetrical.

Thanks for the help.

This is just the sort of thing you could do with PowerPoint so I would assume you can do it with NeoOffice Impress or Apple Keynote.