I built new crossovers for my speakers a couple of weeks ago. I used hookup wire from DH Labs. They have a nice variety. I used 18 gauge on the crossover components and 14 gauge to the new binding posts. I got the amount of Cardas eutectic solder I needed from Ebay. I'm very happy with the results.
3 caps and a resistor shouldn't be too hard to make. It wasn't easy but worth the effort. And a nice sense of accomplishment. There are YouTube videos you can reference.