If you are looking to have a reliable WiFi solution where you will have multiple WAPs covering a wide physical area, and would like them to broadcast the same SSID, you can accomplish without even considering a WiFi controller. Fairly easy and affordable. Worked great every time for us.
Consider Cisco WAP 551.
It costs a couple hindered dollar for each Cisco WAP551. They are P0E. Once you configure the first one which usually takes 10 minutes, configuring the 2nd one would take less considering you can enable the “Single Point Setup” which acts as a cluster, so once you assign the 2nd WAP an IP address, and join it to the cluster, all configuration will replicate from first WAP to the 2nd.
Pretty easy and straight forward setup. Works perfectly especially for those who are looking for zero hand-off when roaming through the space. This is what we have experienced. Some people have reported 1-2 seconds for hand-off.