I noticed when looking around that most clip on fans for tents suck. They don't oscillate, and the few that do seem to break quickly. Most clips won't hold onto a grow tent pole very well either. This is my simple solution. These fans are slightly larger and move more air, they oscillate and...
You might want to rethink the platform that you set up. Your plants will need the height. What kind of exhaust fan/filter do you have. You can house that on the outside of the tent. Clip on fans are great. Small oscillating fans or the towers for the corners also work fine. Anything to move the air under the leaves.
I have a 4x8 as well. I have a oscillating tower fan on both ends of the tent to blow air across the canopy and the top of my lights. I use empty shoes boxes to raise them if I need to. I also have a 6” oscillating fan on the bottom to move air underneath the canopy on both sides. For exhaust I use an 8” exhaust fan to pull all of the hot air out and filter the smell. Good luck