120GB might not be enough. For tight budgets its usually cheaper to go with a HDD. If you think that 120GB will be enough though then it will give a slight performance boost. I recommend this one http://www.amazon.com/dp/B00461G3MS/?tag=pcpapi-20. The $30 you save could go to getting a more powerful CPU such as an i3-2100.
Graphics Card - HIS H675F1GD Radeon HD 6750 1GB 128-bit GDDR5 PCI Express 2.1 x16 HDCP Ready CrossFireX Support Video Card with Eyefinity $95
This is my first build...
Well for the price i'd say go AMD 9XX Phenom II, 4gb ram, 500GB 7200rpm HDD, Case is owner's preference, and at least a 550 1GB card or 7750 1 Gb card. Also you will never be happy with a 350W power supply, need to go closer to 400 to 450W.