in general logitech makes good speakers and for the price they will be hard to beat without going into the realm of home audio speakers. as far as sound cards go, most in the $30-100 range will work just make sure they support 5.1 and the different surround sound decoding (dolby... etc)
Thanks for the reply, had though about 7.1 but my room is so small I feel it would be wasted. I have never bought a new sound card before, the realtek onboard audio my motherboard came with does the job, but I have read other places that the sound card makes a huge difference is this true?
as long as you bought a decent quality motherboard with decent audio onboard with the features you require you should be fine. i've used both integrated audio and a cheaper soundcard with the same set of speakers and any difference is minimal.
in general only buy what you need. for most pc audio situations a low end sub $50 card or integrated soundcard is fine. what you gain from a dedicated soundcard is a bit more quality and a few more options but nothing i would consider earth shattering.
audiophiles make it a huge deal. just like how gamers think a $50 mousepad makes them epic gamers.
a smart person would get the speaker system first and set it up. if everything sounds great then there is no need for a card. if you dont have the options you want or you wish the signal was a bit cleaner (again, audiophiles) then you may want to look at soundcards.
After a certain price tag, move away from PC/Multimedia speakers and consider dipping in the used Home Audio market - better sound, proper driver/tweeter design, etc In The UK that would mean places like Gumtree, etc
Dipping into to the used home audio market like batuchka said is really the way to go if you want really good sound. 7.1 is a waste in a small room and considering that most movies or games don't even use 7.1 so it isn't needed. Soundcard wise it can make a difference if you need high sound for music recording and etc.