Here's another trick I learned in the Army (only kidding) that I have done many times with good results. Since you have two 57's why don't you set them up as the drummer would hear. So the point is to get the sound closest to what you would hear if you were playing the kit. Always a good sound, this is what keeps drummers drumming after all. So set up your 57's just behind the drummers ears facing the drums, but make sure the drummer won't knock them. they should be raised mabe a few inches above his head or try setting them about waist height (do a test in your room) kind of pointing towards the snare on the Left and the kick on the right yet parallel and evenly spaced and aimed at about 45degrees down off horizontal. Experiment, you might like the results. The drummer acts as a kind of baffle to increase the stereo image, but the 57's if eq'd correctly will produce enough low end to compensate for the kick and place it in the middle of the mix. The rest of the kit will sound natural. Basically you're replacing the drummers ears.