If you're looking for general purpose computing and light gaming, believe it or not, you're better off going with the AMD APUs. With the integrated graphics they can actually do L.o.L at very good framerates even up to 1080p - so 720p should be a cakewalk for them.
In addition, they're decent general purpose quad core processors and will easily handle your internet browsing and basic usage that the patrons will be needing them for.
You can get the A10-7700k for about $100, while the Pentium (perfectly respectable chip on it's own) will run about $50-60, and a 750ti will be another $100ish.
FM2+ motherboard - ASRock has one for about $45.
Paired with a 2x4GB 2400mhz Corsair Vengance kit - $47 it should be plenty capable of what you...