Resistors

I would not spend the extra money on Path Audio for the woofers. I would use the Mills MRA12 resistors in that position.  They are also great and cost $5.

That sounds like good advice to me, especially if budget is a constraint, but it may well be that upgrading the woofer resistors will also make audible improvements. I don't have experience with that but I did directly compare 160V and 250V versions of the same cap on my woofer boards (shunt caps, at that). It was a subtle thing, and some songs sounded pretty much identical thru either channel, but overall the thicker film channel sounded a touch more full, with increased ease of presentation, and a bit more bass heft/impact (most noticeable on kick drums and such).

Path Audio is the perfect resistor i have ever listened, you can also check from there to consider the difference :

http://guneytuncer.blogspot.com/2017/03/resistor-shootout-duelund-pathaudio.html

Hi
I will also keep in mind the MRA12 for the woofer.
What type of wiring do you recommend, solid core or multi-wire in copper or silver?
Thanks again for the advices.

what wattage are you looking for?
I like Mills, Path and if you can find them in your value, Riken and Shinkoh.

What type of wiring do you recommend

FWIW, I used Straightwire 18 ga solid on my new boards anywhere the cap or resistor leads were too short (or with foil-type coils which have no leads). But I used Cardas litz from the terminals to the boards and boards to the drivers  (various gauge depending on input or output and woofer versus coax board). I made no attempt to sonically compare the Straightwire to anything else but did compare the Cardas to the OEM 18 ga solid (unknown source).