Lsi15 crossover

Hello all,
Have a pair of lsi15 want to upgrade the crossovers. I have the schematics. But don't know what brand of caps, resistors, wire gauge ect.. to get also see a lot of discussion but no real builds available. Someone said don't use stock 5v use 10v. Would the 5v be better for protection so it goes(pops, shorts, burns) instead of the speaker?
Only consensus is mills resistors. But also seeing different ohm ratings posted. Schematics say 2 ohm. Link from forum users are for 3ohms. Caps haven't see much about them. I'm thinking about just keeping everything the same specs just better parts. But if crossover can be improved would like to do that. I'm sure is this has been answered before. Can't find it. Would buy new if I could find any, and if price is affordable. But can't even find any for sale. So asking here for suggestions.

Also the 8"woofer. Is there any suggestions of new Polk Audio (don't want another brand) woofer that is available and plug and play? Keeping with the 4 ohm. I'm not hating the bass. But not wowed by it either. If I can improve for decent price would do so. Suggestions are db840. But can't find any found db840dvc. Don't know if they are the same. Or if the specs are the same. And if they will fit.

Using a Marantz 5008 receiver, yamaha p2700 amp.
Bi-Wired with actual 12 awg solid strand copper wire.
Powered with Tripp Lite LCR 2400 line conditioner. Just recently read not to use with an Amp. Any options?