Buy Macally USB Wired Keyboard for Mac - Compatible Apple Keyboard with USB Hub (2X Ports) - Full-Size Mac Keyboard with Number Pad - Plug & Play for MacBook Pro/Air, iMac -
OEM Apple White Wired Keyboard A1048 M5769 with USB Port for iMAC G3 G4 G5 iMAC | eBay
This iMac 24-matching hub adds the ports Apple left out - SlashGear
Want USB ports on the front of your new iMac? Try these hubs - CNET
24-inch iMac Ports: 4 USB-C Ports and 1 Headphone Jack, That's All