PC as my music system, advise please.

Hi,

I'm going to turn a spare mid-range PC into my primary music system. I 
have a few questions concerning components to get - I know people will say

you will have a quality loss using a PC rather than high quality audio 
components, but I am physically disabled and have been converting my CDs 
to FLAC, so that I can use a point-and-click interface (WinAmp) to play 
any 'CD' I want. I can live with a small quality loss for the convenience 
of selecting and playing music with a few mouse clicks.

There are so very many audio components to choose from, I don't have a 
huge budget but would like advise on what components are good within my 
price range.

Firstly what I am going to do is connect my sound card to an external amp,

which will also have my CD player attached, and then mostly play music 
from the PC through the amp to its speakers.

a) What sound card should I buy? --I'm not a gamer, the sound card is just

for playing music through. Someone suggested a Creative SoundBlaster X-Fi 
Xtreme Music, URL below, but others say Creative is not a good option.

http://uk.europe.creative.com/products/product.asp?category=1&subcategory=208&product=14066&nav=0

b) What Hi-Fi amplifier?

c) What speakers to connect to the Hi-Fi amplifier?

Re. parts b) and c) - there are just so many to choose from, I started 
reading some reviews but honestly I am a bit daunted, the reviews are 
aimed at hi-fi enthusiasts and not at a newbie (my current CD, Amp, and 
speakers were bought in 1991). My budget is about UK£300 (approx. US$600) 
for both amp and speakers but I don't even know which to prioritize, 
should I spend UK£150 on each, UK£200 on an amp and UK£100 on speakers, 
the other way around, etc.?

I'd very much like some advise about this, and am hoping there are some 
gurus reading this who have some serious knowledge and are willing to 
share their expertise.

Thanks all.

PS. In case it makes a difference I am in the UK.