Old is New Again meme. ;) True: rooms or safe's are best route. There's also more suppliers for that and more willing to work with non-defense customers. However, you've always been limited on desktop and notebooks in high security assessment given all the functionality (esp wireless) in them. There's just way too much risk. So, I recommended hardened thin-clients/monitor/keyboard/mouse plus key servers in a shielded room, no wireless anything, shielding of building from external signals where possible, and of course a lot of distance around the building. Costs quickly become an issue and most just don't do TEMPEST/EMSEC at all. Open season when the attacks get democratized. ;)