This model uses a stock drive from the supplier Apple used at the time. The thermal sensor is stuck onto the drives case. So yes you can use any replacement HD that meets the SATA II (3.0 Gb/s) spec. You want one that is settable not auto sense if you can help it as there have been issues on some drives not dropping down to SATA II from SATA III.
Also you do want to make sure you have the latest firmware on your system. Here's a link which will walk you though it: EFI & SMC firmware updates for Intel-based Macs
A little back story here:
In later versions of the iMacs Apple leveraged the internal thermal sensors the HD vendors had started putting into their HD's so they could better monitor them during burn-in at the factory. Two of the pins on the settings block where used. These were still stock drives but each HD vendor did things differently so Apple had to have a few different cables to connect to the pins. This is when you needed to swap out the HD with the same manufacture (if needed you could switch out the cable).
Later Apple had a custom firmware made and using the power connector connection the temp sensor was then done that way (it should be noted the HD vendors dropped the settings block in these HD's). This is the problem with the '11 model on forward.
Apple did go to the standards group to add the sensor method so all HD's would follow the same method, sadly we're still waiting on its inclusion into the standard.
In the mean time some HD vendors have moved forward making some of there HD's compatible with Apples method so you do have a chance here on getting one to work (talk to the HD vendor to see if the drive you are getting works).
Also there are people making an external sensor which you can splice into the power cable to make any drive work (the way I do it).
Lastly, there is a software solution you can use but it depends on the SMART reporting which creates issues as it requires added interrupts if you are doing heavy I/O computing it gets in the way (very large vids or CAD drawings as an example). Which is why I don't recommend it. For a light weight user it's likely to be fine.
Hopefully that untangles things for you - Good Luck!