Not strictly an ESL only amp the Magtech is available for a 30 day trial.
http://www.sanderssoundsystems.com/products/amplifiers/magtech-amp
Not exactly plug and play, a Bruno Putzeys design. Hypex restricted power supply (350W @ 8 ohms) in the DIY offering, but far more intriguing design than most current class D. These component modules should soon be making their way into higher powered designs from other amplifier marks (Channel Islands?). Some initial DIY reviews claiming a huge sonic leap forward in switching amplification.
http://www.hypex.nl/index.php?option=com_content&view=article&id=100&Itemid=102