Maybe I can help too. I've played live using backing tracks since the 80's using Midi and Computers. I've used a variety of configurations from a 100lb rack of hardware synths and effects to now where all I need is a 5lb netbook.
What you need to decide is how complex your backing system needs to be. I find complicated systems are often the ones that fail you at a bad time. Also ease of set up and not having to "mix" songs live or fuse about at gigs is important to me. So I prefer well mixed stereo tracks to multi track output.
The most important thing is to test your songs through the PA over and over. I use Wave Lab to master my tracks and set the average RMS level so all song are equal.
I make the tracks in Sonar. I'm always re doing them as the instruments ( VST) improve over time. I use both midi and real drum parts and mostly real bass. Right now I'm working my way through 120 songs and upgrading them all.
In 2003 I bought my first Laptop and have used more or less the same system since then for hundreds of gigs with out ever a problem. Because I'm not using a DAW for playback any POS laptop will work. Just shut off the wireless.
I play guitar and sing.
My set up involves stereo Wave files of Drums, Bass and some keyboards parts.
I use Win Amp to play the songs.
I use an X Keys USB footswitch to start/stop and advance the playlist.
I use Notepad to display lyrics ( only on a few new songs)
Win amp is the only player I know of that can be set to STOP playback after each song.
I have lots of information on my web site here:
http://www.cactusmusic.ca/johns_rig.htm