Paolo:
I think this is getting more complex than it could be.
Here’s the scenario:
1. Client provides an ad, either as an attachment or pick-up from a print version (don’t worry about the quality here; I know it will be poor).
2. Using the media library, scan ad or click on “add new” and add it to the media library.
3. Using the image widget, I click on the ad and it is imported into the widget hit save and it fits. I can delete the image widget if WP has an integrated plugin to accomplish this.
4. What size does the ad have to be in order to fit the space? You suggested 500px. Telling me that it’s responsive means nothing to me, sorry, I’m not a coder or dev person.
5. If I’m spending all this time writing code and adjusting the ads, I’m not making any phone calls therefor no money.
6. I’m looking for a fast and simple way to insert the advertiser provided ad so it looks as good as possible in the sidebar without writing code every time I want to drop in an ad.
7. An example in the right sidebar can be seen here: http://www.ruralintelligence.com/ Yes, I know they are not using WP.
8. If this is a directory program, I’m pretty sure Stiofan already thought of a way to make this happen.
Thank you