I've been using a type of slosh panel, a Summitek Cradle, to develop 4x5 negatives for the last few month. I recently moved up to 8x10 and last month I asked Summitek and Photographer's Formulary if they had any plans to manufacture an 8x10 negative version of the 4x5 negative slosh trays they both sell. I just got a call from PF yesterday saying the trays for 8x10 negatives are in.