I wouldn't even suggest AMD these days for a entry level PC until they can prove they can perform on par with Intel, which they haven't been doing for the past 3 years. Also the i5 3470 was cheaper than the best AMD processor out currently. I assume your friend means bottle-necking (CPU limiting the GPU and vice versa) but no it's not going to happen.
You can look at some performances of the 2 CPUs here and even compare some other stuff.
http://www.anandtech.com/bench/Product/702?vs=697
The 660Ti is $270-300 so I didn't even think about it since that's about a third of a budget and it would have limited me to getting lower quality parts. Video cards are always getting better and dropping in price so I recommended the 7850 since it has the best performance to price ratio. I would have recommend waiting for the next generation AMD video cards since it's going to be 20-40% faster then the current generation.
I don't really recommend overpaying for a motherboard if you're not going to utilize all of it's features like overclocking or using up all of your video card slots. The z77 pro3 is amazing for under $100, you can overclock well and it has room for another video card to do a dual GPU configuration. Not to mention you get a discount because of the combo.
The case isn't bad but the cooling is decent and cable management is iffy.