There is an excellent recent Harmonia Mundi recording of this work (Herrewghe/Collegium Vocale Gent), typically fine HM sound and an excellent performance, which has a lot of extras with it -- a CD-ROM, a booklet, etc. Another highly regarded one is by John Elliot Gardiner on the Archiv label. If you enjoy the performance you attend (Rilling is pretty good, from his other Bach discs I have) you might be interested in looking for his recordings of the work on Hanssler and Sony Classics (Hanssler is probably a better recording). And I do hope you enjoy the performance at Valparaiso!