it would be grat with a single page where modules could be added to create a facebook businesscard. Maybe some sort of template, where you have acces to put in some of the products you have, Topics and maybe even customer reviews.

Integrating it on facebook is not that hard.

You create an application here
You can deside if you want to show it in an iframe, or as FBML

I created this FBML some time ago. EdgeProInc, (be sure to tick Like, this is not my site, but the guy deserve the tick. )

The disadvantage with FBML is that you have to write the whole thign from scratch. and upload new code if you change anything.

In an IFRAME you can use things allready in existance. But i dont need to tell you guys about things you allready know. :-)

Eventually you will end up with a page looking similar to this one.

If you type this line into the browser and change the  appid and the url, you have the choise to deside whics fanpage you want to have a tap on for your app.

https://www.facebook.com/dialog/pagetab?app_id=YOUR_APP_ID&display=popup&next=YOUR_CANVAS_URL

The hardest part is to design the page to show in the Iframe, thats where a predef Nop page would come in handy. :-) You will simply create your facebook businesscard like a pussle of things that are allready there.

And changes will be made instantly. :-)