laptop graphics: should i stay with an Intel 4000 or get nVdia 640LE?

[tracerit]

I'm configuring a laptop to be used for the following: web browsing, youtube, watching 1080p bluray rips, and other basic things. the CPU will be an i7-3610QM with 12GB RAM and a SSD. I'll be working on multipage Excel reports and watching the bluray rips in the background. Will watching the video stress the CPU where it'll take away resources from me working on the Excel reports?

[2is]

Stick with the IGP, it's more than good enough for those tasks and then some.