Depending on what you want to do with this system. If you want to play games that require some horsepower, get a decent discrete graphics card.
If you're content with medium settings then a mid-tier graphics card will suffice, saving you money from the purchase and power consumption.
If you want high-ultra settings, you might have to go with a high end card, depending on the game, resolution and frequency you wish to play on ofcource.
Often, u can look for a decent second...