Check out the Klyne Audio Arts 7PX5. It's a solid state unit with a wide range of gain and load settings. Here's a link to their website but it hasn't been updated in a while. I'm using this with my Airy 3x SB with good results (although I only have about 20 hours on the cart). Mehran used to own a 7PX3 which is the previous model. List is about $5k but it's hardly seen in the used market.
http://www.klyne.com/
http://www.klyne.com/