I haven't heard much about gigabytes boards. I've heard a lot of people love ASUS boards. I personally own an MSI x58 platinum at the moment and have been disappointed by their quick overclock switches on the board. I manually overclocked in the end and have been fine.
I see that the board you recommended now has multiple monitor support for sli/crossfire. I prefer nvidia so I may sli somewhere down the line if sli now works with multiple monitors. That is one of the primary reasons I have never gone with sli is because in the past(or at least when this computer was built) it did not support more than 1 monitor (I only use 2 monitors).
Are gigabyte's boards reliable, easy to overclock, and well designed for components to comfortably fit?
Lastly in the past I've had to purchase a network card for each computer I've owned. I noticed that this motherboard has a 10/100/1000 Lan Chip which I assume is for LAN only. Any chance I'm wrong and I could plug my ethernet cable directly into it from my Uverse modem or do I have to just buy another network card?
"Are gigabyte's boards reliable, easy to overclock, and well designed for components to comfortably fit? "
Yes, yes, and yes. They are a top tier manufacturer, on par with, or some people would even say better than Asus.
You would not need a separate lan card with this motherboard.
I'm also building a system right now, and like you I settled on the 3770K and tried to build the system around it.
Instead of the 280, I decided on an Antec P183, because I could get it from EndPCNoise.com with 12mm acoustic foam and Nexus fans preinstalled (quiet is one of my higher priorities). Very happy with their service.
I used an ASUS board in the last system I built, and my wife's audio studio workstation also used an ASUS - both were solid performers, never had any technical problems, and the driver and documentation support on the website was pretty thorough. I'm not a diehard supporter of the company, but it's what I have direct experience with, so I'd recommend them in that sense.
For my new system, I wanted to use their brand for the motherboard again. Like you, I decided ahead of time that I wanted a socket 1155 i7 processor. Just a few posts down from yours, you'll see I have a thread of my own asking whether I should get one of their Z68 boards that are out now, or wait until the new Z77 boards come out in a few weeks. Take a look, it might be relevant to what you're asking.
Both the P8Z68 (available now) and the P8Z77 (available soon) meet all your requirements. I don't plan on buying a PCIe 3 card now, but I'd like the option in the future, so this was something I wanted. Both boards support PCIe 3, but the one that's out now does it through an IC that was added to the board, while the upcoming Z77 board has it integrated as part of its basic design. Technically, both should support PCIe 3, but it's uncertain whether the difference in implementation could cause a problem.
The advice I got, which I think I'll follow, is that the price of the Z68 boards certainly isn't going to go UP. So unless I *have* to have my system built in the next four weeks, I should probably wait for the release of the new Z77 boards and see how they fare in the reviews.
If you're considering ASUS, I'd suggest the same. I'm not sure what the other board manufacturers are offering that has PCIe 3.0.