Just looked and nothing available other than LED taillights like the 2011+ vans have, and the standard earlier tails.
I'd go with a junkyard pair and experiment. You can mix clear and black paint to spray them just like nightshades, or wrap them in smoked vinyl (easily removeable if you don't like it). If you could get an early 5th gen set of tails, the lenses are pretty flat (just one curve) so might be easier to heat up some clear acrylic sheet to form your own outer lens from. Cut to shape after bending/cooling and fit. Then you can paint the inside of the light and use colored LED bulbs and add red reflectors where needed (by law, rear and side). Light output for back-up lights may suffer, so you could plan to add auxilliary back-up lights somewhere else.
At least this is a project that can be done indoors over the winter months!