You definitely need help from someone who knows how to build speakers and has the equipment to test the drivers, and the software to calculate the appropriate crossover components for the chosen drivers, as long as they are designed to work together.
No, you can't use any 1550 Hz crossover. It has to be designed specifically for the drivers used, based on their Thiele-Small parameters.
Frankly, it would be a lot easier for you to return what you ordered if you did, and get a flat pack will all the necessary components from places like Parts-Express, Madisound or Meniscus Audio Group.