i did a rap record with a singer who had just totally out of control plosives. i ended up using a beyer m201 with the giant windscreen attached to it. and it worked out like a dream. let me throw this one up on the list.
at the time i didnt have my 441... i would try that now....
and jeez i could see trying the 319 as well. when that mic works it works really well. especially for $99.
you might want to try two flavors, like a 421 and an oktava 319, good to mix things up in rap. like use one mic on verses, another on choruses... or double up the vocals one on each mic.
really recording rap is pretty tough, i wouldnt do a all in one mic. some rap tracks sound just great lo fi as well. dont throw away that 57. go to garage sales and pick up "tape recorder hi-z" mics as well.
sorry just here to confuse you. a used blue bottle might work as well...