I don't know if you should consider a 2.4 GHz design for any HD deployment. There simply isn't enough spectrum to properly service the depth of clients and there is no 40 Mhz 802.11n or 802.11ac on 2.4 GHz. You really limit yourself with 3 non overlapping channels.
Hope this helps ..
"Satisfaction does not come from knowing the solution, it comes from knowing why." - Rosalind Franklin