i used the fans from a 89 nissan sentra. its a 11.5 inch fan and a 10.5 fan. i bought the fan for 50 dollars at a junk yard. all you gotta do is run both power and ground wires in series. then find the power and ground wire from your electric fans. then just splice the wires with the butt connectors. the only thing is htat you have to make custom brackets to get the fans to fit. this is because only one peg lines up at the bottom.
there is also another alternative. you use the fans from a G20 or a B13 sentra with a SR20. those fans will fit perfectly on the radiator. both bottom pegs line up, and the two top brackets line up too. the thing is though, you have to buy 2 of them. one primary and one a/c condensor fan. they are also generally more expensive.
the results of my fans are really good though. i would use to over heat when its 65 degrees outside becusae my intercooler is blocking too much air flow to the radiator. it would only overheat if i'm stuck in traffic for an hour. and i can forget about turning on the a/c beucase it would overheat instantly. after i installed my 89 sentra fans, the car can sit in traffic for hours and hours, and even with the a/c on, the temp needle would not go up. it was a very good investment, but you need to be creative to get them to fit right.
edit: and yes i did feel a noticable difference in power as well.