Ive always used Flexalite 1250 cfm fans. They are clean, have a rubber seal around them, Fit nicely and push a ton of air and are thin to fit in tight spaces. Im using a single one now with my civic half width, 2 core radiator and it cools perfectly, When i had my full size radiator i was using the dual flexalites total of 2500 cfm and they move some air. They are expensive though but they last forever, very high quality, and dont have to worry about them.
As for your question about which way to wire, it all depends on what way you want the air to flow. Almost any fan can be a pusher or puller, It all depends on which way you wire the fan up. If the fan was originally called a pusher then i would have to guess the blue would be positive and black ground, If you want it to pull just wire it up opposite. If the fan was originally stated as a puller, the blue is again positive and black ground. If you want it to push, wire it up opposite. Its easiest to just test it out with a battery first before wiring it up to be sure. I would suggest that.