What kind of speakers do you have? What kind of drivers? How much money do you plan to invest?
I just rebuilt my Altec 604E crossover using original crossover schematics. I just use original inductors. Capacitors in most vintage speakers are of very bad quality, especially electrolytic. Potentiometers also are very bad for sound.
Vintage Altec drivers are very well built with huge alnico magnets and good quality diaphragms. So they are really worth the investment. I can say, these speakers with original and rebuilt crossovers are completely different speakers.
I used Duelund resistors. Mills are transparent but don't hold complex music as good as Duelund.
For the 14uF capacitor I used a mix of: Duelund RS, Jupiter VT, Auricap XO, Dueuland Silver bypass.
For 3uF I used Jensen Aluminum foil PIO and Duelund bypass Cu-Sn.
But I reused most of the capacitors from previous projects.
For good value for money I can recommend Auricap XO or MIFLEX KPCU-01/03 if you want really high quality copper foil capacitors.