Is this system good? Are all parts compatible?

It's wasting a LOT of money. Gimme just a second and I'll write up why.

1) You don't need an i7. The only difference between an i7 and an i5 for gaming is hyperthreading, which gives such a negligible benefit in such a small handful of games that it's ridiculous. Don't bother with that, get an i5 for a hundred pounds less.

2) I would just get a Hyper 212 EVO for cheaper instead of that thing, and then either pocket the difference or spend it on a nice fan or two.

3) I personally don't like MSI's boards very much, but I know motherboard options vary wildly from location to location. If you have (cheap) access to AsRock, get the z97 Extreme 4, it's a very good overclocker. In any case, get a z97 chipset motherboard anyways, to have all the goodies.

4) Great pick on the memory, can't argue there. I would only say that there are cheaper 8GB kits out there, and there's no reason to get anything above DDR3-1600. You aren't going to notice the difference in speed.

5) Good to see you know your storage requirements, but see if you can work a SSD in there. Seriously, having a 90GB or 120GB ssd gives such a crazy improvement to how smooth and responsive the computer feels that it's ridiculous.

6) Great pick on the graphics card; I can see that you like MSI, and that's fine for graphics cards.. but ditch the 4GB card. There's no reason to have that much VRAM unless you intend to game at 1440p or 4K, and a single 770 won't do 4K worth anything, and in order to get good framerates at 1440p, you'd turn the settings down just enough so that you wouldn't need more than 2GB of VRAM anyways. Save the money, get a regular card instead of the ripoff with bonus VRAM that's never going to get used.

7) I've never heard of the Comrade, but I like BitFenix quite a lot. However, that's a very cheap case, so know what you're getting into. The side panels are going to be utterly frustrating, it's probably unpainted aluminium on the inside, and the front panel will be prone to breaking. That's going to be true of any case that cheap.

8) You're going overboard on the power supply there, mate. That PSU would be sufficient to power TWO GTX 770s, much less one. You only need a 550w power supply of reputable quality... and could even use a 500w PSU without any struggle, but 550w gives you a little more overhead for overclocking. I personally really like the Seasonic G-550, but there are cheaper options out there.

9) There's absolutely no reason to buy windows 7 Professional. Just get home premium for less money. (I personally would absolutely get windows 8.1 for the actually functional bluetooth, the fact that it can be transferred from computer to computer, unlike windows 7, and that it doesn't have artificial RAM limits like windows 7 does.) Do a little research... but after ten minutes of customization and getting used to pressing the windows key, windows 8 is bloody fantastic... the people who don't like it are the ones who just tried the metro apps and want something to complain about.

Anyways, that's my advice. Oh yeah... if you do get a cheap case, it will have only one or two fans, and they'll be cheap and noisy. Consider paying a little bit more to buy yourself two or three good fans to replace them and make the thing a lot quieter and cooler.

With the money you saved you go upgrade from a 770 to a 780? Or you could get a ssd with that money aswell?

That's a very strong build, but I wouldn't go with the Pro 3. If you can afford it, get the Extreme 4 - it's a much nicer board that overclocks way better and has better features.

You can also go down to DDR3-1600 RAM, which is not going to make a noticeable difference for anything but benchmarking, and will save you a little bit of money.