I feel like I stumbled onto an Audiophool thread: If the connectors are expensive, they MUST be good!!
Seriously, be aware: I have had the opposite experience: I have some Pomona jacks that are gold over nickle (and lousy mechanical quality), and the Mueller posts that are gold over Te-CU (104 alloy). Ordered probably a few years ago. Of course generally you don't use TeCu wire, so regular 110 copper works also...when it's clean.
The "Low Thermal" jacks are suspect also - I'm holding one in my hands, and its gold over what looks to be thin electroless nickle. I contacted the owner, who confirmed that he didn't think they are actually TeCu, and couldn't confirm the exact coating process. I thinks it's a replacement part for whatever instruments he reps. They aren't worth the price IMHO. We tested them at the lab and they don't work 25 times better than our self-built $1 posts. They work about the same, actually.
He's also got spade lugs which are garden variety spades that are gold plated. They aren't TeCU either. You can send any crimp lugs to a plating house for gold plating, it's cheap and common. They don't work any different than the 12 cent spade lug without the plating.
We just machine our own posts from TeCu or regular 110 copper, keep them clean and skip the gold. The gold only adds a few uV noise - maybe a little more convenient to keep clean but we never use it. Use a ceramic or teflon insulator, and regular nuts / washers in copper. Use colored nylon washers at the base for color coding. Skip the expensive "Low Thermal" leads - clean copper works fine. The silver-coated stuff is stiff and hard to get a repeatable compression on. Sometime on finicky setups we use teflon - insulated wire - but watch out for how that material cold-flows and creeps into crimped connections. Use guard circuits well, and then the wire type is even less important.
For resistor standards under 10k you'll be using 4 wire anyway - and if designed right the binding posts won't matter much.
The bottom line: Mount your binding posts on a good thermal conductor, keep the copper connections clean, and use a small, precision torque wrench on spring-loaded nuts to make a repeatable compression force on the wire - that will make more difference than thermal volatge anyway. The thermal voltage will generally not be an issue if both binding post are at about same temperature, so keep them covered and draft-free.
SKIP the BANANA plugs if you want repeatable readings. Those really have no place in precision measurements, usually.
This is how its done at our cal lab, and is by far the most cost-effective way to get repeatable results even into sub ppm range. We ditched the expensive low thermal connector baloney years ago, and never looked back.
If your binding post system costs more than a few dollars per post, it's maybe not the best way.. at least that's what we've found out during testing.
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