HAF Stacker
Yeah it's too long for an ITX case as that's not really what it's for. It's sorta like a spare room for a full size PC, which happens to be able to fit an ITX motherboard. Both versions are kinda cool, but neither seems like it's worth it for building a standalone ITX case.
Coolermaster V700 PSU
Great quality PSU, but kinda overkill for any ITX build as there is only so much power you can realistically draw. It's also 170mm long, which is outwidth standard ATX dimensions, and will cause you compatibility problems with a significant number of ITX cases. It doesn't mean there are no cases it will fit in though.
This chap is using one in a very compact case without any major drama.
You should maybe consider which bits you want to change. You seem pretty happy about changing the case, but do you want the keep the PSU if possible?
Bitfenix Prodigy
It is smaller than your Dead Silence, but not so much that you'd really notice. Also, the Prodigy is going to have issues with the V700 due to it's length, though you can mod a fix, it's perhaps a bit specialist.
FT03 Mini
You have two problems here-
■ A GTX780Ti is too long for a standard FT03 Mini. There is some sort of mod in place to allow a Titan to fit in that case. You can see from the way it is sitting that it's a little longer than the aperture. I don't have the experience with this case to know how viable this is.
■ PSU. SFX is currently limited to 450W but there is a 550W Silverstone Strider on the way too.
As for the viability of an i7 and a Titan on 450W, it's certainly possible. Most tests of power consumption you'll see on tech sites are done using full ATX motherboards which use more power for obvious reasons. Also, that i7 is at a relatively low overclock (people get up to maybe 4.8Ghz on a 3770K) meaning it won't be using vastly more power than stock.
Their figures seem fairly believable though. The GTX Titan has a tdp of 250W and most tests suggest it can pull around that figure. The delta between idle and load - 240W. If anything it's their idle figure which seems a little low.
Your issue is that if you have an Impact, you presumably want to push the processor a bit, so you'll likely be pulling quite a decent chunk of power over their figures, your processor itself is a little more power hungry, as is the GTX780Ti over the Titan. All of those things together, and personally I'd be a little nervous about 450W, but 550W would be more than enough.
Your problem is that if you want to keep your PSU, then you are likely to need a larger ITX case such as the Corsair 250D (which also fits nicely with your desire to add a liquid cooler, whether its a proper loop or an AIO) but that isn't going to be a lot smaller than your Dead Silence (similar width I think, just shorter).
Have a look at the link below, and keep in mind that you are currently limited by 170mm PSU size.