You can save the songs as Video if you need the chord sheet, then just play them from a media player playlist.
You can also use a little hardware LCD media player with the Video songs on a usb stick.
Some media players have RCA L/R out to the PA, but if you just want to use the laptop you can use the headphone out as long as it's a good socket you should be okay.
If you look on eBay you can get a usb foot switch that can be programmed to any key for pause/play/next/previous songs or for use with the Conductor feature in band in a box realband.

http://www.ebay.com/itm/USB-3-Triple-Action-Foot-Switch-Pedal-Control-Keyboard-/320927559891?hash=item4ab8c5f0d3:g:vc4AAOxybetSBb--