Ping limit is set at 250. Server is 12 hours difference of EST. So, 6pm EST is 6am in game. Lets late night players enjoy playing in the day time without playing on a server located in another country.
I would recommend ASUS for the company just based off of my experience. But, EVGA is also pretty popular, which is the first one I had linked you. http://www.newegg.com/Product/Product.aspx?Item=N82E16814121625
You could check out this one. GeForce GTX 560 Ti, someone may find better but for $300 that may be one of your best bets. I had a GTX 580 and it ran the game no problem. Might be good enough for ARMA 3. RAM you might want to check out with the spare cash. 8GB would last you a long time. http://www.newegg.com/Product/Product.aspx?Item=N82E16814130604