Lenovo IdeaPad Z50-70 or G510?

I'm going to get a new laptop but can't decide between these two.

The Lenovo Z50-70 looks like a great laptop for what I want which is to be able to do my uni work and also be able to do some moderate gaming.

The Lenovo G510 however is only slightly more expensive but it comes with and I7 core processor rather than an I5 core processor and a different graphics card and lower resolution. Apart from that these laptops are pretty much identical from what I can tell.

My concern is, from the descriptions of the laptops on the website, I can't determine if the G510 comes with the dedicated graphics card or just that it is able to be upgraded.

I'm not sure which laptop to go for and if i really need and Intel Core I7 processor or not.

What are people's thoughts? Which would you go for out of the two?

Thanks.

Lenovo Z50-70 - http://www.ebuyer.com/624118-lenovo-z50-70-laptop-59416331

Lenovo G510 - http://www.ebuyer.com/614840-lenovo-ideapad-g510-laptop-59406131

Added (1). Also, do you think i will need a cooling pad for it? If so what would you recommend?

At this stage, i5 is plenty fast for most people. I7 is overkill unless you do some demanding job like video editing that needs all the CPU power you can afford. For gaming, dedicated graphics chip is the way to go. I suggest you go for the Z50.