A tape backup system is needed, so the company will be able to get up and running quickly in the event of a crash. It should also insist on at least two connections from the server to the Ethernet switch, with failover support in the event of one of the adapters, cables or switch ports causing problems. Once the network is running you may well want to capitalise further on this investment with a network fax solution. There's also the matter of security to consider, with a firewall being the most obvious solution. However, as with Company A, it's not going to be permanently connected to the Internet, so a firewall isn't essential.
Virus protection is a priority, installed and managed via the server.
The company may also want to consider deploying some kind of systems management software. This is the simplest setup for the network to allow shared applications and reasonably fast ISDN Internet access. Palmtop PCs can be left attached to individual computers for personal use, or run off a main PC if more than one user is required per device.