We were just going through the same 'dilemna' recently with a lot of good reflective type songs and only a few uptempo numbers. We've done a few older well known worship songs with a much faster beat, and that has gone over real well. We have also found a few nuggets that don't get played in most churches, but have really caught on here because of the message they contain.
Also, Kutless is a well known Christian band that has taken some older worship material and redone it in their unique style. "Take Me In" is one of many that we do by them that have been very well received with the fresh take. http://www.youtube.com/watch?v=Q0cuOawD_I8
I can send you chord sheets to any of these, but there are sites on the web where this stuff is available.
May God bless your search,