I have no experience. Not yet at least.
But was proposing to use on a similar project an Iiyama PLT1930SR/19 for £385 from ebuyer - 19 inch monitor. And put it together with
Acer Aspire Revo R3600 Desktop PC, Atom 230 1.6GHz, 160GB HDD, 1 GB RAM, HDMI, nVidia GeForce 9400 ION, WIFI, Linux
Which is on sale at ebuyer for 150. Or use some other atom based sff machine, but this one is so cheap.
I was thinking of getting one of those compact flash to ide adaptors, then using the debian variant that is firefox only, so its basically debian with the only thing on it a browser. I guess you could do it yourself, but this is prepackaged. There is also browsermode linux. There seem to be a couple of these around.
We are a little way away from doing it, I first have to do a demo not on a touch screen, then get funds committed if they still like it....
Peter