I actually just finished a similar project with my dad. It's a much larger scale ( 4x4 stand up shower, and a spa surround ), but we used the pre-made mosaic things too. It sounds we have the same Lowes saw you mentioned, too. It works pretty well, but kinda gets water everywhere.
Any questions you may have about artistic tile, or bathroom refinishing in general would be answered by going to the Hamilton Parker store. The place is downright awesome, you should definitely go there and discuss what your plans are before you start. You will not be dissappointed, the place absolutely delivers.