SATA controller

Hi list,

I have to build a linux box (TSL2.2) with 24 750G hdd's (sata) for a  
someone who needs lots of space. (app. 16 Tb raid-5 with hot-spare).  
This box has to act as a nas server for a win2003 box.

I normally use onboard sata ports and sometimes a 4 port sata  
controller (fakeraid), all combined to make a raid-5 md device.

Does anyone know there are controllers with more sata ports or is it  
wise to use (very expensive) real raid controllers in this case?

Suggestions anyone?

Thanks,

Ariën