DIY project speakers

Hello, I have a pair of PSB-B25 speakers I recently contacted the skiinninja to upgrade the current crossover network, now I am curious since this is the first time that I will do any DIY project w speakers. The internal wiring looks cheaply made I would like to upgrade all of the internal wiring, now what kind of wires can I use or should I use that will make a lil bit of a difference and improve the sound? Also, what about solder material? What kind Should I just buy cable at Home Depot and replace the current ones or can someone recommend a better option?

Thank you!