There is a third diy option :
If you have can find an old netbook you can :
Install Ubuntu on it ( I think it's only some versions, but they are all available on the Ubuntu website). I can check the version I am using if you are interested in doing this.
Select "share printer with other systems" on the netbook.
Connect the printer to the AirPort Extreme by Ethernet / wifi.
Connect the netbook to the AirPort Extreme by Ethernet.
Turn off wifi on the netbook.
Set up the printer on the Ubuntu netbook and give the printer a name you want to see on your iOS devices.
You will then have iOS printing for everybody in your house 24 hrs a day. It has worked flawlessly for me for two to three years. The only issue I had was Ubuntu didn't always reconnect automatically to wifi after a power cut, so I just turned off wifi in Ubuntu and connected the netbook by Ethernet.
We have various Macs in our house, but they have multiple user accounts and two are laptops, so having a cheap throwaway netbook always in place 24hrs a day is much simpler for the non techies in the house. In fact I don't think they are aware of the netbook. They just know they can print from their phones.
