I have a client who has ~800 domain names that are currently parked and generating some serious monthly revenue but the parking host is getting the vast majority of that revenue. The domains point to no content at all, other than the usual links that the parking host provides. My client wants me to take the 800 domains and create a single page template that, based on the domain/url that the user points to, the content would change.

To clarify:

Ideally, a single page 'template' would be used for all the domains. On it he wants a video feed from Amazon, some google adsense stuff, etc. The video and content would all be based on the domain.

~800 domains, for example (and no, he doesn't have these awesome domains : ):
gardening.com
fishing.com
movies.com

If the user enters in fishing.com I'd like the page template to load in fishing video content (he's going to provide the code for all of the content from a content provider) in the video player portion of the template. And in the right-hand side, the adsense would change based on the domain.

Is this possible? Or do I just need to create 800 different pages, basically the same except for content-specific code?

I'm a flash developer with some xhtml/css/php and java experience. My client, who I've worked with on other projects and he really trusts/likes me, insists I do this for him even though I have zero experience with non-flash-based dynamic content (or AdSense, etc).

Any advice as to what approach I should take for building this thing out would be greatly appreciated.

He could use a script that fed the domain name into the keywords of a product feed and then displayed products based on that keyword.

likewise, he could try to apply for a Google Domain Parking publisher account and use Google Ads to monetize the parked domains