I have done a little testing with this and here is what I have found. You can have the markers for the locations be specified dynamically like you are trying to do. Here is how I did it. I first made sure that I had the images for all the different colors and styles of markers that I was going to use. I then had to store the image and shadow image names in the individual records in the db.
Once all the images are available and you store the image and it's shadow in the db you are ready to alter the code. In your wagmp_maps_1.php you will need to find the location where the markers are set, then copy this code into the loop just after the do statement.
Once in the loop you can add in your reference to the column that stored the image you want to use like this:
This will get you all of your points showing with the markers you specified in the db. If you are having trouble with this please post back with a URL where this can be seen and I will take a look.