My wireless router is a Linksys BEFW11S4, has built in firewall, 4 port switch and DHCP. Has a pretty easy to use web interface to setup the box. It's at most computer stores for $179, but I got mine off ebay for $150. Try doing a search for BEFW11S4

I just looked on ebay for regular 4 port hubs and found them for under $20, but you will need DHCP service running somewhere, possibly a windows server of linux server can do that easily. I used to have a netgear 4 port hub a couple years back in my house and didn't have dhcp running at all and worked fine for me. I was also able to share my dial up connection w/ 2 other computers in the house. Ahww, the good old days.