AN Niobium versus Tantalum resistors?

My favorite combination is using the z-foils in series positions and the AN silver tantalums in shunt positions. The higher wattage silver tants sound a bit richer but don't fit everywhere. 

I haven't tried the Niobiums. 

Takman's take on induced noise makes sense with the naked Vishay, but then, induced noise would predict lower transparency, resolution. I believe pretty universal experience TX2575 highest resolving, transparent resistor. Issue with these, wattage and lack of flavor, as previously noted these won't supply your needs.

In any case I'd like to hear your impressions of these resistors if you decide to try.

 these won't supply your needs

excluding compoents from consideration based on pure speculation made on the basis of what you read is rather unwise IMHO.

@pesky_wabbit I very much doubt the Z foils will deliver what OP desires in this particular case, reason I suggested Takman carbon films over Z foil.

And my suggestions not based on pure speculation as you speculate in regard to my experience. I have in fact been using the Z foils for years, many in my Merlin BAM, in previous dac, in former phono stage, in Art Audio Carissa Sig, in my present 300B monoblocks. So, plenty of experience, again, I doubt these will give OP what he desires. Also, wattage will be of concern, TX2575 just over 1/4 watt, yes, you can stack for greater wattage capability. In the end I believe OP is on correct path, he's done due diligence here.

Caddock MK132 have the signature the OP is looking for.  These are discontinued, however their replacements the MK232 should fit the bill as they share the same construction and have undergone only minor changes for Rohs compliance.