hi joe
theres loads of good soundcards worth considering and the soundblaster range from creative would normally be the first choice of anyone looking for a soundcard
however in the last 18 months asus have released a selection of soundcards that are as good if not better than the creative range of cards... and they range from just over £30 right up to £200+
the "Asus Xonar DS 7.1 PCI Sound Card"( http://www.aria.co.uk/Products/Components/Sound+Cards/Asus+Xonar+DS+7.1+PCI+Sound+Card+?productId=37596 ) is the entry level soundcard from the range and has some excellent specifications for the price
it has a 44.1 kHz (min) - 192 kHz (max) sample rate and the sound is generated by the ASUS AV200 audio processor.....it has a Signal-to-noise ratio of 107db and supports the standard 32bit pci bus interface
connections are plenty with line in/out, mic,and surround jacks.... there are no larger inputs however this can be fixed by purchasing some simple adapters
then theres the "Creative Sound Blaster X-Fi Xtreme Audio 7.1 PCI-Express Sound Card"( http://www.aria.co.uk/Products/Components/Sound+Cards/Creative+Sound+Blaster+X-Fi+Xtreme+Audio+7.1+PCI-Express+Sound+Card+?productId=39863 ) which has a better selection of ports .. and also has integrated digital optical input and output which is a nice addition
so with that in mind the x-fi extreme would seem the better choice.... however the best soundcard you could buy has to be the "Asus Xonar HDAV1.3 Deluxe PCI-Express Sound Card"( http://www.aria.co.uk/Products/Components/Sound+Cards/Asus+Xonar+HDAV1.3+Deluxe+PCI-Express+Sound+Card+?productId=39555 ) ... this has more features than you have ever seen.... you name it and the HDAV1 has got it
infact theres actually two cards and the quality of the sound is second to none... and for home recording theres nothing better, however be sure you have 2 x pci-express x1 bus interfaces.. allthough most modern motherboards have at least 2
alternatively and slightly cheaper you could go with the "Asus Xonar D2/PM 7.1 PCI Sound Card"( http://www.aria.co.uk/Products/Components/Sound+Cards/Asus+Xonar+D2/PM+7.1+PCI+Sound+Card+?productId=39544 ) ... at half the price of the HDAV1 this soundcard is remarkebly good and has all you would need for a home studio
and more importantly it has the required digital input and outputs both with Coaxial and High-bandwidth Optical Combo Connectors.... theres also 4 anologue outputs (Front/Side/Center-Subwoofer/Back) and 2 anologue inputs (Line-In/Mic-In) ...so taking this into consideration the Asus Xonar D2/PM is probally the best choice.. and costing just £89.29 inc. VAT it represents excellent value
i hope this helps,any problems let me know
good luck joe !