I have to work with the choir I inherited from when our church was traditional hymns only. I also have to incorporate a classically trained pianist. This works out great when we still do traditional hymn services once a month. As we've moved into the contemporary realm however, both have been a challenge that sometimes wears me down. Many of the most popular modern music is not choir friendly and the repetetive simple chord progressions of say a song like "Everlasting God" leave a classically trained concert pianist wondering what to do with themselves.
Still, with lots of prayer and God's help, we manage to pull it off. Having a choir does make it take substantially longer to introduce new songs as my folks range in age from 17-63 with a wide range of musical skills or lack thereof. It takes a great deal of practice to get them all singing somewhat together. When we do have those monthly hymn only services however, I wouldn't do it without them. As far as what role "Classically Oriented" songs should play, I limit them to the prelude and an occassional offertory performance just to let the pianist stretch out a little. Once in awhile I will even accompany her on violin. Depending on your service format, I'd think there could be place for classical performance and that it could be quite beautiful. I'd just be cautious about becoming too performance oriented. Our primary goal is the engage the congregation in the act of worship, not entertain them.
With regards to how a high church choir sounds in a contemporary setting, here is a recording of us from Easter. Disregard my guitar being so out of tune. I had done a sunrise service in 29 degree weather about an hour earlier and my strings continued to go flat for the rest of the day. My hands didn’t seem to warm back up for awhile either! Keep in mind that this is a former high church singing choir, a classical pianist, a beginning bass player and a drummer whose been playing about 6 months now. God is good!
My Savior My God - Choir Style