Praise Charts is one of at least two sites which specialize in full orchestrations, besides offering lead sheets. See their song list of available orchestrations at:
PraiseCharts Song List
They have a well-organized database behind their site, which will cross-reference titles from a number of worship albums, by authors, arrangers, etc.
Worship Albums
Don't overlook PraiseCharts' list of their top 25 downloads from CCLI's Top 100:
PraiseCharts Top 25 Downloads
If you're not a member already, PraiseCharts has a sign-up offer: free and immediate access to the complete arrangement of Praise Adonai by Paul Baloche. If you ARE a member, you can get a modern arrangement of Joyful, Joyful, We Adore Thee for 35¢.
www.praisecharts.com