I am building the NX Center crossover in the same way I built my Otica crossovers.  I am using plexiglass as the base for mounting all the components.  Drilling holes and running all the wiring shrink wrapped in black, over a black base.  This way, you wont see the “mess” underneath.  Looks very clean.  I use 3M hemispherical rubber standoffs.  Then on the black base use plastic chromed feet so there is no metal messing with the inductors.  Looks metal, all plastic.  
Initially I planned to use the supplied sonicaps and GR wire wound resistors with a foil inductor upgrade on the mid.  I received all the parts and just couldnt help myself but to order “upgrades” for everything.  The only thing I didnt customize was the large inductor for the lower woofers.  A copper foil of that value would be the size of a basketball and cost a fortune.  I looked into into it.  Not worth it.  
For the rest I had planned to use all hard to find miflex copper foil caps (miflex out of business) until I saw some of the values could not be sourced.  I settled on mostly a complete Vcap ODAM nest of caps utilizing Deulund silver copper CAST hybrid bypass on the tweeter and miflex coppers on the mids.  I used miflex coppers on the other smaller value caps as well.  For the resistors I like the Path Audio resistors.  I know Danny doesn't like them because they have metal ends.  My personal choice only on those.  I upgraded all the inductors to copper foil except the big woofer coil.  
The major point of back and forth was using the provided tube connectors.  I elected to go with pure copper binding posts.  I know, I know, the higher mass copper might lose performance.  I just like the flexibility and look and ease of installation that a solid copper post provides.  My really nice, already ran through the wall, speaker cable utilizes bananas and this is just a simpler solution for me.