I was browsing the new Altronics catalog this morning.
It lists a new item, with the catalog number H5050. Unfortunately, the website hasn't been updated to include it.
It is a 2U rack mounting case, with the heatsinks already built in to both of the sides. The front panel is 5mm alumunium, and from the photo, looks to have a very nice finish. The catalog price is $195.
I'm not exactly sure it has the correct dimensions for the AKSA 100, and probably the heatsinks will need machining to accept the transistors, but it looks quite promising. It lists the dimensions as being 425W x 300D x 88H.