The laptops will be entirely separate - linked via wireless network adapters. They won't be able to access the PC network, unless you equip it (the network) with a wireless access point. Why don't you operate the whole lot as one wireless network, using a wireless access point and wireless network adapters?
Network switches are more expensive than hubs, and although they can bring substantial benefits in a large network situation you wouldn't notice the difference on a small home network. Switches are 'self-learning', and generally work by reducing collisions on the network, relieving congestion. They also break very large networks into smaller sections.
To be honest, network switch deployment is a pretty big and complex subject (get it wrong and you can actually slow a network down), and isn't one that I can go into fully here - suffice it to say that I would recommend a hub in your situation.