You really need to narrow it down to area of interest.
I took a class from Karen McTavish and she was phenominal. A great speaker, entertaining, personable. However she may not appeal to your guild.
http://www.designerquilts.com/teaching.html
If you have a lot of member interested in domestic machine FMQ, you should consider Diane Gaudynski.
http://www.dianegaudynski.net/workshops.htm
Maybe Leah Day would come, I'm not sure if she has expanded to the point of travelling for teaching or trunk shows.
http://www.daystyledesigns.com/lectures.htm