I wonder if Chris Licciardi (Cubesmith) will be there this year - he was there last year. If so, you'd be best off just getting them from him.
If not, I bought 5x5x5 stickers for backups and for when the V-cubes arrived - I have one set I can spare for the price I paid ($1.50). They're the generic stickers for use on either Rubik's or Eastsheen that Cubesmith sells.