I know a million people have already asked this question but I would just like everyone to make a suggestion or two, I'm really green on what to buy as far as an audio interface for inputing custom guitar riffs and mic input. I have a p4 1.6 inspiron by dell with 256 ram which I will buy more as soon as I can. But it seems to do the trick. Would you guys just offer any suggestions as far as beefing up my system and also the audio interface of choice? all I have is the oxygen 8 keyboard.