crossover components

You would need(for each speaker)..

1 3.3µF and 1 40µF Polypropylene (or other of good quality) capacitors
1 40µF, 1 50µF, 1 1.5µF and 1 8µF capacitors which doesn't need to be of an expensive type
1 1ohm resistor of good quality (maybe a metal-oxide resistor)
2 8ohm and 1 20ohm resistors, wire-wounded would probably do
1 5.0mH inductor with low series resistance (Rdc)
1 0.4mh inductor, preferable Cross Coil or CFAC
1 0.3mH and 1 5.0mH inductors of some general(cheap) type