Compatible Video Card Replacement for iMac

Hi Everyone.

I have an iMac "Core 2 Duo" 2.4 20-Inch (08) Serial number W88128843ZE2.

The information I have found on the ifixit forum only details the 07 and 09 models from my understanding rather than the 08. However, I know this maybe because these models are similar to my 08 but I wasn't sure and I didnt want to assume before taking this project on.

Nevertheless, I wanted to know if the current Radeon HD 2400 XT 128 video card my Imac currently has can be replaced? The information I have obtained researching this question online has been very contradictory, so I thought I would ask this forum since I have used it to fix other items which have worked perfectly upon following the outstanding ifixit manuals provided. Thank you by the way to all those who have contributed

If the video card can be replaced what brand or video card can I use to replace the old one? I have also researched this question but answers are contradictory as well. I do not need anything special I just want to obtain graphics on this system again to use it.

Thank you