On the subject of usb input or line-in input striaght from a guitar I have to agree with Eric.
I have a Behringer Eurorack mixer which provides all the impedance/phantom power etc I will ever need. Line level stuff straight into a PC line-in is OK but it's nice to have control over how the signal is recorded. They're not expensive--if you're paying £1k for a guitar the this little beut is peanuts for the cost.
http://www.behringer.com/EN/Products/UB802.aspx
There's one on eBAY for £40 !! Forget anything else you may need for your hobby, my advise to anyone on this site for a bedroom player is to grab it before it goes. There's buy it now so just buy it !!
http://www.ebay.co.uk/itm/Behringer-Eurorack-UB802-8-channel-professional-mixer-/330688383103?pt=UK_Mixers&hash=item4cfe90487f
Bri


