Best sound card for £200 or so

I'm looking for a sound card at around £200, higher priced suggestions still viable. Must support 5.1 surround sound and preferably also a headphone amp / thing to improve my already great 7H's sound quality. But only if there would be an improvement over my 7H's sound quality. As I don't want a headphone amp that I won't use. Currently have a logitech 5.1 surround sound speaker system, would like better sound from them, and "Improved?" base.

Sound on my 7H's is already great for me but if there is a headphone amp + sound card in one that would make them better then I'd take that over just a sound card.

I do like base a lot in music and games (Who the hell doesn't like actually feeling their gun's  every shot fired  in BF3 or being deafened by tanks in PS2?). So I want very clear sound, but also the ability to beef it up a little with base, still with clarity to it though.

Also, what amount of difference would a good headphone amp make to my 7H's? Same for my 5.1 surround sound system, what difference would a good sound card make to them?

I dont think many of us have experience in that price range, but take a look at Asus Xonar line, Creative Labs  Sound Blasters and HT Omega makes some nice stuff. Here's a comparison chart of their Claro Series: http://www.htomega.com/faq18.html

Claro Halo XT seems to have all you could ask for, headphone amp included.

For you last question I can only say that there is clearly a market for these so I guess they do make a difference.

Only problem being that I'm completely new to sound cards, haven't a clue what anything on them really is or means. Looking around myself too, thanks for the suggestion.

The Xonar STX is pretty much the best card on the market now, and it's under $200.

https://www.asus.com/Sound_Cards_and_DigitaltoAnalog_Converters/Xonar_Essence_STX/

+1 for the Xonar Essence STX, it's amazing, you will have eargasm (99% sure about this) the next time you put on your headphones :D