Minecraft noob in need of video graphics help

Hi,

I'm a noob when it comes to Minecraft but I was looking to buy a computer as a Xmas present for my son. He loves playing Minecraft and would love the ability to play using 'graphic mods.' The computer he's currently playing on right now is unbearable and lagging.

I was looking to buy him a Dell XPS 8500 that comes with an i7-3770 processor and 8gb ram. I need help picking out a video card if any redditor out there could help me.

I have the option of the base 7570 card or adding the GT 640 DDR5 OEM version for 75 dollars more. I also planned on buying my son a 24 inch monitor (1080p resolution). I know absolutely nothing about Minecraft and its video graphic needs.

Will a GT 640 DDR5 OEM version run Minecraft smoothly on a 1080p monitor? Or should I try to buy another video card and learn how to put it in myself.

Minecraft is the only game he's interested in now and looking to play. Thank you for all the replies in advance