"better" as in price yes.. not better as in faster/powerful as the old cart. But for gaming, the 1-3fps guessing on average you loose from the last cart is not worth it for the difference you just saved IMO.
If you could fit an SSD in it... Idea is you install Windows + a few games on the SSD you play the most.
VS, CX, RM Corsair PSU's aren't very quality I don't think.. heck that isn't even 80+ certified. Probably fine though if it saves you a ton of money.
Corsair's higher end PSU's are made by Seasonic, just like most brand's "good" ones are made by Seasonic:
http://whirlpool.net.au/wiki/psu_manufacturers
Silverstone usually has above average products if there name is on I think. I wouldn't be afraid of a Corsair branded one even if it was a lower end model. Esspecially if your saving $100. Having good quality capacitors/cooling/modular/design is a "nice to have" not a "must have". A freebie PSU that comes with a case would be much worse than a low end corsair psu.
I didn't look at the mobo very close but it certainly has less features than the last one. Some of those features like Overclocking you probably didn't want to mess with anyways... but other features I don't know what you want and what you dont. If it suits your needs anything will work that's the right socket.
If space is an issue in 6months / year... just purchase another Hard Drive. I'm partial to RAID/NAS (i.e. WD Reds or Seagate NAS) drives as of the last few years. They should inherently be a little more resistant to vibrations and overall longevity while still providing similar performance of a standard 7200rpm drive. You pay a bit of a premium for them to but here the price difference isn't that bad especially if you catch a sale.
*edit*
The case. Since the price is lower, I would guess it has less features. I don't know much about either one, just glanced at features didn't study them closely at all. Some cases have neat quirks or something that sets them apart... small things from rounded edges, cable management locations/tie locations, design of internals, how easy it to route or not route cables behind the motherboard, how hard drives mount, the fans and ventalation, front USB3.0 ... things like that are the things to consider. Large cases are generally much more forgiving than a tiny one.. just by being large it'll make it easier to work on and put it together.