Buy a Netgear FS108. It's an 8-port 10/100 switch. Just use it with your existing hub (put all the slow kit on the hub).

http://www.microwarehouse.co.uk have them for 40.99UKP ex. VAT which is 10UKP cheaper than I've seen elsewhere.

The FS116 is 16-port and is 70.99UKP.