Vislas can be real nice (I'd be interested in one some day myself) but they have their foibles that you and your dad should be aware of.
First, unlike GSP's for example (where many dogs from widely varying backgrounds can be counted on to be good hunting dogs with training--due to stability within the breed) you have to do your homework when getting a "V".
If I were getting one I'd look only towards proven hunting dogs I had watched work from breeders I could trust to answer my questions--or from some of the better field trial lines with proven doggie game history. I'd want a dog with a LOT of bird intensity/drive for a "V" (some of them just aren't that driven to hunt and thus are tricky to train).
Vislas are "softer" than most dogs. They don't take harsh training methods or pressure well, and can shut down or take a lot of work to bring along if you don't take things slow. They often take a while longer to develop, and are very clingy. They don't want to be away from you so seperation anxiety can be a huge problem if they need to be alone for any lenght of time. People call them "velcro" dogs for a reason. I wouldn't advise getting one if you don't intend to keep it in the house with you, if you need to crate or kennel it for most of a day. If you want a best buddy that will always want to be right next to you wherever you are, and don't mind learning about training and are willing to take it slow, they can be fantastic dogs.
I wouldn't have any idea of where to begin with Visla recommendations out your way. For GSP's I might check into clubs. Here's a newsletter from one in NJ:
http://www.egspc.com/Forms/TNLT%20Issues/Tick%20N%20Liver%20Tales%20Sept%2009.pdf
This kennel has a pretty good rep.
http://www.honeyrunshorthairs.com/
Here's a few from Maryland that may not be too far away, breeding looks good, I've no doubt pups from any of their breedings would work out fine for you:
http://www.friedelsheim-gsp.com/ http://www.fieldmastersshorthairs.com/
Couple of others I can't say much about but might be worth checking into:
http://littlewingkennels.com/ http://www.cruzinkennels.com/index.php
Good luck!