Depending on the grid - Hang the Oktavas around 8 feet apart and around 12 feet high in line with the conductor (over first violins and cellos). Just hanging - Pointing straight down. This is going to give you a great, but slightly exaggerated stereo image. Will also give a great audience if this is live.
With the SP-1, you'll have to work around the conductor - Over his head is fine, but they usually have something to say about that if it's a live performance. Chest high in front of him is nice, but they have a tendency to smack it.
If there's room between him and the violas, put it closer to the violas, a little above stand height, just SL of center and pointing slightly SR, favoring the woodwinds (reverse this if the brass is favoring SL). This mic will be in mono, highs rolled off a bit, and brought in well below the overheads. You want to "feel" it - Not "hear" it. This will "glue" the stereo image together, giving you a very nice representation of the conductor's point-of-view in the end.
Whatever you do, CHECK with the conductor to see if it's positioned out of his way. I consider the "glue" mic to be the "art" mic - It needs to be there. If you have to put it on a shorty a foot off the floor, but in front of the conductor, do it. You're going to get too much viola and second violin, but again, it's there for "spice" and "glue" and not much else.
The 57 - If there's a particular solo instrument that needs a little reinforcement, you might use it. If there's a harp, you might put it very close to the soundboard to give it a little extra help.
If the percussion is too damn loud, put it near the percussion (but don't actually record it). If they see that mic so close to them, they might not "overplay" as much. I've done this probably a dozen times, and it works like a charm.
A winsdscreen on a 57 looks less like a 57 also...
