Are u going to use it often??? iron nickel
Cos, if you are, you might as well buy them. sm57s are quite cheap on the market, brand new for $125, people selling 2nd hand for $80. The md421 is not that cheap, you've got to look around. As for condenser mic, you can try behringer b2 pro, Audio technica at4033a, or maybe rode nt-1,nt-2 or ntk. Can get one for $300. Try searching in Simlim for cheap prices, or often i see people selling 2nd hand.
Renting is still quite expensive, and only recommended if it's just a 1-time project.