One thing I can suggest is that if you have the time but don't think you have the skill, there are a number of tutorials on this site for building maps. You could use GIMP(free) as well as freely available(ie, those licensed for non-commercial use) brushes found here or other places to create your map and we will help with the input of us here via a work in progress thread. Most of your map looks easy enough to do with some help and time spent on your part and you could get something you are proud of(though it won't look like the linked map!). If you REALLY want that style, the artist does do commissions here, but I believe he(Djekspek) will likely require payment, especially for something of this style since it takes FOREVER to do this type of map.