Try the Waves (waves.com) site and select the GTR option - Waves Solo is is available as a free download (free use for 1 year). The problem is that it is a VST plugin that does not work in RB or PTPA (so either record your guitar in another sequencer or export your Biab or RB track to another sequencer and record the guitar).

Take note of Mac's advice re the impedance matching (this is in fact very important) - I use an M-AudioFast Track Pro USB unit and it works great for guitars as it has line and instrument input options. Several manufacturers have less expensive USB input devices for guitars - see also the Line 6 site.
Roy