About $1300, but which model?

So, I have two questions, 1. Does this build sound suitable, and 2. Which model to buy? Many thanks.

Budget:
About $1300, but I could increase or decrease if needed. I could find the money, but I don't have the time to justify buying a high-spec system.

Expectations:
Will drive a single 1920x1200 BenQ monitor. It's been out of use for a while, so if that's broken, I may upgrade to 1440p, possibly with G-Sync.

Usage:
Gaming, web and some general usage. Games will likely include strategy - Europa Universalis 4, Crusader Kings 2, Civ 5, and others genres too, The Witcher 3 is likely to be the most intensive.

Special Needs:
Prefer smaller case, but flexible.

Saved Ticket #:
Eclipse 1300202

Specifications:
Something like this, I'm open to suggestions:
i5 6500
8GB RAM
1x250GB SSD + 1x1TB HDD
GTX 950
DVD Writer
Air cooled
450 or 500W PSU
Standard Intel overclocking only

My question, though is this: I can get this setup from several different Digital Storm models, and the cost of them is different. Is the cost of the different cases what causes the price difference, or are there other differences too? I've aimed to make the setup as similar as possible.
Eclipse $1310
Bolt 3 $1535
Slade $1276 (with Corsair Carbide Air 540)
Apollo $1276 (case as above)

Thanks again.

Thanks, that makes sense. I have been mostly keeping away from cheaper mid-towers and bigger because I'd prefer something that is smaller and doesn't remind me of old 1990s cases, but the Vanquish still isn't a bad looking case, and the better value may be worthwhile.

I'll think about increasing to the 970, too. I've never felt a big need for really high graphics detail with high frames per second, but the 970 would stay useable for longer, so may still be the better choice.

Thanks.