Fluid mounting 8x10

I want to fluid mount my 8x10 negatives with an adjustable height holder, but I noticed that the one offered by BetterScanning only goes up to 5x7. Has anyone found a larger one? I looked into having one made from aluminum by eMachineShop, but it is very expensive for one, but around $85 each if 10 or more are ordered, $70 for 20+. Would anyone else want to have a custom made holder for Epson scanners for up to 8x10?