I'm sorry to make this confusing. you are in Australia I assume? If your hub is a wireless hub the WiFi iPad will work. From what you are telling me, both of computers have to be connected to some device in order to access the internet. With a WiFi connection which is the way the iPad works - you need WiFi.
I can take my laptop anywhere in my house and it is not plugged into any device and I pick up the wireless internet signal from my router which is connected to my cable modem. Same thing with the iPad. No wires - no cables - nothing plugged in and I get the internet. Unless you can connect to the internet without being plugged into some sort of device, you better ask before you buy the WiFi only iPad. I just can't determine if you are using a WiFi network in your home with the information that you have given me so explain your home setup to whoever you talk to before you choose your iPad.
If whoever told you that you need 3G is someone that knows your home internet setup, then they are probably correct about which iPad you will need.