Civ 5 and Total war are both CPU heavy games (this is a general rule for strategy games, especially RTS's), and CSS is more of a GPU heavy game, although the quality is so low that it doesn't really matter. The i7-3930K and GTX 675 will be able to handle these games no problem.
SLI is more for performance benefits than future proofing, but if that's what you're concerned about, then yes, two GTX 675's in SLI will run just about anything on highest or near-highest settings for a long time.
Ice didn't put RAID in his config because in his setup he only has 1 HDD (and 1 SSD), whereas I had 2 in mine. You can't use RAID when you only have 1 hard drive.
The network cards are only a bit different. My assumption was that the more expensive card is more powerful, but I don't have a whole lot of experience with high-end wireless cards (still stuck on Realtek LAN myself
). In a review that compares the two, it looks like the card in my build has an advantage.
Of course, this only matters if you have a good internet connection (and by good, I mean stellar, like 30+ Gbps), which almost definitely won't be the case if you are deployed
The battery for this laptop looks pretty set in stone, but there is an option to get a spare.
Another thing that you may want to think about (especially if you go with SLI) is to get a good quality cooling mat. The GTX 675 is based off the GTX 580, which is notorious for getting real hot real fast. I don't know if NVIDIA has solved that particular issue with their efficiency buffs, but it's something to think about.