Do it with the CA cards. Do you have a choice where to sit or is it reserved seating? If it is a free for all, sit at the 1/3 mark in the center of the hall. Can you wear em in a hat? Also, keep the levels conservative and allow headroom for those double and triple fortes. Orchestral music is suprisingly loud and amazingly quiet when it wants to be. Probably some of the hardest stuff to record for extreme dynamic range associated with that kind of music. Totally 24bit worthy while most PA amplified concerts are not, IMHO.