I'm not sure what you would need to do to get adobe web gallery working I don't think putting it in a text/html module would work though.  Probably create the folders it needs on your web server and set it up as you would normally and then create a page in DNN that links to it's first page in the photos directory.  I've never been a fan of adobe web gallery as it looks cheap and a little amature.  (sorry).

Your better bet would be to go with the core gallery module here.  It's much more classy and professional looking. You are trying to sell an incrediblly beautiful property for $16 million dollars I think it would be best to present as professional site as possible.  As it is everything will probably be take out and rearranged by the buyers agent in hard copy to be presented to anyone that could afford it anyway. :)  So you have to capture the buyers agents attention.

It's really easy, easy as any of the other modules and not as involved as everything you would need to do with the adobe stuff. 

You have to be able to log in as host to your site. It's still officially beta and works with DNN version 3.2.2.  I don't think it will work yet with DNN 4.0.2.  You can get the install zip file from the gallery project page and there are a couple of files where I made some changes for other people having problems until the guy running the project can make a new release.  Those are on my site and you can download them there.

Check out the gallery module in action on my site www.phdavis.com for a idea of what it looks like and how you can use it.  Since I'm feeling especially bored right now if you want send me feedback from my site and I'll help you through it over IM or something.