i made good experience with a small mixer (Phonic 6 - Channel, Behringer will work as well best ist Mackie).
I plug my Gits into a simple Stompbox (Ibanez Powerlead) and from that into a Mic-Input, than used the EQ to get a acceptable Result (one have to lower the highfreq to cut the typical lineincreeching...).
The Masterouts of the mixer go directly to the linein of the soundcard, the lineout to the Stereo...
For better results a small ampsimulationbox does wonders.
good luck