Sounds like you've got the wrong radiator and wrong electric fan for the application Andy. You can make anything work with time and/or $, but I suspect you'll be better off in the long run if you get the right parts to fit the car.
The shroud makes a big difference with the stock mechanical fan. If you're gonna run the mech. fan, you should definitely have the proper shroud in place. As for the electric, pullers (mount on the backside of the radiator) are more efficient than pushers (mount on the front of the radiator). I'd be VERY suspect of a $5 fan's ability to move enough air to keep your car cool. Assuming this is a V-8 Mustang (no sig - what car, engine, year, mods?) you really need at least 2000-2500 cfm without a/c, and 2500-3000 cfm with a/c to assure keeping the car cool in those NY summertime traffic jams. If you don't have data on the fan, I wouldn't put my motor at risk with it. Can't help you with the hose sizes/part numbers.