Thank you for getting in touch with us on this matter.
Yes, you are able to add custom markers to your map with our plugin. You are also able to external links to the description as well.
If you want to check out our existing features, this section on our site – http://wpgmaps.com/demo/ – may be able te show you most of what our Pro plugin can do. It also has links to what the Visitor Generated Markers does as well as the Gold.
Does this perhaps help answer your query?
If you need anything else, please get back to me and I will be happy to help you as best I can.