I can't get you to the exact download page, as his site doesn't like Firefox, but if you go to http://www.deanbelcherphotography.com/ click on ENTER SITE, then go to the downloads section, you can get the photo from there.
As for RasterBator - go to http://homokaasu.org/rasterbator/
In there, you can either use an online version, where you upload the file, and it does it all for you online (good for Mac users like me), or you can download a Windows program which gives you a bit more control over the dot size etc.
Hope this all works out ok for you.
Ps, I just blew up the image in Photoshop, added a little grain, and a 'half-tone-pattern' filter to it - took it to a printer, and got it posted at full poster size just for £11. It looks 10 times better than the Rasterbator idea. I'll post an image when I get home tonight.
Success is merely a failure to imagine more