Several companies manufacture computer aircraft servers.
… Flight Display Systems is a relative newcomer to the Military and Special Mission market. The benefit of their products is they typically use the latest technology and have better customer support. Their FD200CPU-12 is the most powerful of their aircraft-certified computer servers. Product Family Page.
… 3/4 ATR Aviation Processor with Removable Mass Storage. This is a custom-built product, so we assume that they do not stock it in inventory or have a fixed price. It is based on modular PC/104 computer boards. More info on Parvus aircraft server.
… ETI Services has the great domain name of Military-Computers.com where they sell many Rugged Airborne PC products. Such as the AMC-1000 Dual Core PC. These products are designed and qualified and engineered for use in harsh Naval, Airborne and Ground environments. More info on ETI Services Inc.