I looked for about half hour last night, but unfortunately I couldn't really find anything. If you want to be safe, you may want to just go with the i5 system cause it should do you for a few years.
Oh yea it was real impressive the performance I was getting. I had to customize the settings and turn off AA, a few settings were on low or medium, but for textures and a few others I had it going on high settings. I was playing at close to 1080p too so it was doing real well. Heres a review if your interested:
http/www.notebookcheck.net/Intel-HD-Graphics-4000.69168.0.html
A graphics card still performs better and I understand wanting to have one in your system, I am just saying don't look too closely at vRAM. If the laptop had for example the old ATI 4250M which has various sizes of vRAM, the Intel HD 4000 out performs any version of it by a good bit. Back when I was testing the Intel GPU I think I came to the conclusion that it was about half as powerful as the Nvidia 620 in performance, and thus about equal to the Nvidia 520M but with lower power draw. The 7670 and 7650 graphics in the two other laptops do a good job and just about give double the Intel HD 4000 performance also.
Well personal, I hate Windows 8, and if I had a computer with it the first thing I would do is install Windows 7. So this is a preference. If you like Windows 8 and think you would enjoy it, then I would say its worth the $20 extra. Either way the i5 system is I think the best. Its very close to the one I bought just the other day, but the graphics built in are about 10% faster maybe. The one I got was cheaper, with more RAM and larger HDD, same CPU, and about 10% lower graphics ability, but personally I feel like I am set for the next few years with it since its just a mobile rig for me.
Btw if you ever work on PCs, this one is really simple to take apart to change RAM, or to clean or anything else you might want to do.