Try the audio apps. from HNC at http://www.nch.com.au/index.html, or maybe better the ubiquitous Audacity (with Lame codec for MP3).

For analogue to digital conversion I use Behringer bought from Amazon see http://www.behringer.co.uk/EN/home.aspx

Then research

F-CONTROL AUDIO FCA202
Ultra low-latency 2 In/2 Out 24-Bit/96 kHz FireWire® Audio Interface

U-CONTROL UCA202
Ultra low-latency 2 In/2 Out USB/Audio Interface with Digital Output

U-CONTROL UCA222
Ultra-Low Latency 2 In/2 Out USB Audio Interface with Digital Output and Massive Software Bundle

GUITAR LINK UCG102
The Ultimate Guitar-to-USB Interface to Jam and Record with Killer Modeling Amps and Effects

U-PHONO UFO202
High-quality USB Audio Interface with Built-in Phono Preamp and Massive Software Package for Digitalizing Your Tapes and Vinyl Records

Good luck.


.