Internet Cafe Owner Looking for help with game servers.

Hey guys It's been along time! It was like 2 years ago when I came on these forums and got help with my first two Internet cafe builds. Well let me get to it, I have a internet cafe chain in the Philippines and opened 3 shops in the past two years and I'm opening a new one in December. I go back to the U.S. every year and order my parts at Newegg and this year I need to build 30 more pc's and I'm looking to build a game server to better serve my customers. I have my shops at the major universities in Iloilo City, Philippines and feel having a private server I can ultimately interlock my shops and take my business to another level. I’m a newbie when it comes to these things but I manage to pick out the parts of my builds ship them over here and assemble each computer myself. When it comes to servers I'm lost what would be best for me pay for hosting online build something myself what should I do? I have 85 pc's as of now when I build 30 more 115 in all and my units range from I5-750's,760's,amd x3 445,amd x4 640 with amd radeon 5670,5770 and some older 4870's.4 gb ddr3 g-skill ram,c300 ssd's,win7 ultimate and 23"acer lcd's. Here in the Philippines my computer shop's specs are second to none and these kids play mostly dota,hon,nba 2k11 and other lan games. So pls let me know what’s best for me budget wise I'm willing to spend $120 a month or up to $2,000 to build something myself. Thanks!