How tight are those screws where you removed the air-duct? I have the same case/psu and ended up sticking a 80mm fan on the outside because my HSF is to big, it looks a little odd, and I'm considering removing it as it doesn't seem to do much for airflow being that it flows air (not even a lot, maybe like 30cfm) right ontop of my HSF.
HDTV is 27", I'll add specs to my sig sometime soon. I read on the manufacturer's forums that you shouldn't put a fan on the window, the vibration will eventually crack it. So yeah, remove it and go look for the screws/nuts that came with the case to put just the grill on it. The desk was free like.. over 8 years ago from our neighbors. Only has 3 legs if you can see that (but it's sturdy enough that I'm comfortable putting my tv on it). No one ever used it until now, and it fits my room great.