These people might be worth getting in touch with:

Barandi Citera Band

They organized a week-long citera festival in July 2009 and 2010, so might do it again:

Alfold festival 2009

2009 pictures

Festival 2010

(Everything is in Hungarian, but in my experience Hungarian folkies will make colossal efforts to help anyone interested in their music, even if they know not a word of the language).