Daft Punk

Will monitors be sufficient for guitar rig, or would an amplifier like the Tech 21 PE60 be better?

So I've got my guitar hooked up to my M-Audio Delta 44 and then put into Guitar Rig, from which I have a set of bose speakers (I know, i know) to listen to myself. I'm wondering what I could possibly do to improve my tone. Monitors are on my watch-list, as well as the Studio Projects VTB-1 preamp to give my tone a tube sound. However, would monitors be sufficient for guitar, or should i consider something like a tube power amp and a cab for guitar or maybe a Tech 21 Power Engine 60?