MSI Z87-GD65 or G45
cpu> i5 4670k or i7 4770k
gfx > r280x or gtx770/780

go buy dell pc or tell us what you REALLY want.
which games, price, wanting to spend some money on extra stuff like keyboard or tft etc.
Furthermore as delight say you can build a very silent PC nowadays with like, spending 50-60 euro extra on various parts.

depends what your budget and intented use is to what suggestions can be made.
i5 should do for just gaming and other basic tasks
8gb of ram should be enough
mobo - look for one in your price range that has the features you want. check the manufacturers website for the compatable memory list and get 8gbs of something listed there, this rules out the chance of incompatability issues when you build it, and the need to manually configure timings, i learnt that the hard way(1600mhz range will be fine thats a good price-performance range imo)
personaly i tend to get gigabyte boards, they are reliable, can be affordable, the bios is simple to navigate and usually they have dual bios to avoid the chance of bricking the board in a power failure when booting (saved my ass countless times )
HDD - if you need one then i'd say 1-2tb - personally i would go for a WD Black - performance is standard and had good experience in reliability.
SSD - if you can afford one, then 80gb - 120gb should be enough. reliable brands such as samsung, intel would be my first suggestion as i know they own their own NAND fabs, keeping the best for themselves and bin the lesser quality memory to other brands who stick their logo on it. not that theres anything wrong with the others, crucial and corsair etc are still good.
Cooler - if you're not overclocking the stock fan will do the job, if you want something better, something from Thermalright, Noctua, be quiet, arctic cooling will do. doesnt really matter, just needs surface area (more fins and heat pipes).
power supply - ive not heard of the one you listed, tbh if powering new hardware id not risk running an aged psu. if that dies it could kill every other part of your system with it.
Seasonic make reliable units, some are fanless which is no problem in terms of heat and performance, just personal preference and what your budget is. they also make the units for corsair afaik, and corsair are also highly regarded. i'd say 500w as a minimum
gfx - again depends on your budget, one of the most expensive parts in the build along with the cpu. depends what you need it for, an old 570 will still perform ok in games and can be had for about £100 on ebay. unless you see something you want in the 600/700 series. or wanna go amd.

use your asus sound card as you intended, its still better than any onboard solution. sound hardware doesnt age like other hardware.
i presume you're keeping your existing case.

heres a mockup of a build:
mobo: Gigabyte GA-Z87-HD3
£82

CPU: Intel Core i5 4440 (NON K so cant be overclocked, but the performance is still decent as its a quad core at 3ghz and a reasonable price)
£138

RAM: 8GB Corsair DDR3 Vengeance (CMZ8GX3M1A1600C9)
According to the tested compatability list (http://download.gigabyte.eu/FileList/Memory/mb_memory_ga-z87-hd3.pdf)
£66

HDD:
1TB WD WD1002FAEX Caviar Black, SATA 6Gb/s
£63
OR
2TB WD WD2002FAEX Caviar Black, SATA 6Gb/s
£116

GFX:
depending on your case design and air flow you should decide whether you need the blower or open design cooler - google that. my reason for selecting evga is because of the warrenty.

EVGA GeForce GTX 760
£202

OPTIONAL:
SSD:
Samsung 840 EVO 120GB
£76

Cooler:
(intel)
arCtic cooling freezer 7 pro v2
£15

Arctic Cooling Freezer i30
£29

Be Quiet! Dark Rock Advanced
£33

Thermalright Ultra 120 eXtreme
£41

dont forget the thermal compound:
Arctic Cooling MX-4
or
Cooler Master IC-Essential

both are decent and non conductive

power supply:
Full Modular
Corsair AX760 760W Full Modular
£137

or for a little less money and less power (still more than enough and future proof in terms of gfx card upgrades - sli/crossfire)
Seasonic X-Series 650W
£108

Hybrid Modular
Corsair Builder Series CX 600W
£60

Fanless
Seasonic FANLESS 520W Platinum SS-520FL2
£118

there are plenty of options when it comes to the psu though.
__________________________________________________________________
so to compress that a bit:
Gigabyte GA-Z87-HD3 -£82
i5 4440 - £138
8GB ram - £66
2TB hdd - £116
gtx 760 - £202

Total: £604

optional:
840 EVO ssd - £76
cooler - £15
CX 600W psu - £60

Total: £151

hope that gives you something to think about, probably tmi but gave me something to do xD
this post was fairly biased in terms of manufacturers (intel, nvidia, gigabyte)

Intel Core i5-4670K @ 3.40GHzAverage CPU Mark: 7599

Intel Core i5-4440 @ 3.10GHzAverage CPU Mark: 6521

ssd is better than hibryd sshd because there is no mechanical parts. mechanical drives speed vary depending on heads position, if in the center it is about 100mb/s , at the perifery it falls to 50-60 mb/s or less, also there exists slow sectors.the SSD i proposed gives 500MB/s R/W