It may be a little premature, but I would contact this organization and ask them to help you in your quest:
heroesgifted.org
also contact
www.njagc.org/ if you haven't already - and attend their funtions with calling cards in hand and contact book ready!
Good luck!
Other ideas for finding gifted preschoolers in your area -
1) Chess clubs
2) Muesuem kid's clubs
3) American Girl Doll History Clubs
4) Ask around at the library for a book club for kids aged 4-5 who are reading books similar to what your child is reading.
smiles,
Grinity