Update...
after looking into and trying & discussing this topic
with many of my pro gigging player friends the final solution
for MY needs was a 128G iPad running the
BACKTRAX APP CLASSIC for ios it works flawlessly
to play Mp3's & simultaneously show/sync lyrics with many options needed, custom
Playlists,scrolling,stop after each song,etc,
for musicians that play & sing. I also use a
TRAKFORM iPad tablet holder on a Mic stand which works great also.
using the Bose S1 pro with battery or AC wire.. with a XVive U3 Wireless Mic system Bluetooth really works well and leaves you cable free
http://www.xviveaudio.com/productInfo.asp?id=366