Hello Conor
The 1800 series access points are the entry level access points that can be used with a wireless controller in an environment similar to that shown in the lesson. You can take a look at these devices at the following Cisco site:
If you can find a cheap used Aironet 700 or 1600 which are older series not sold anymore, they too can be incorporated into a WLC enviroment.
I hope this has been helpful!
Laz