I have a bass amp that has a ¼ headphone jack, will I get a good recording if I take the signal, run it into my digital interface and pipe that into Sonar?  Or should I use the XLR output into my interface?  If the ¼ jack works, will it produce the same quality as the XLR? Would rather not have to go spend money one an XLR cable if it’s not necessary.  

its not a good idea to run anything hot into your audio interface.
your just asking for distortion and level overload.

Ok cool, I will go get an XLR cable then.