I'm looking for chip carriers and sockets that will work well down to 4 K. Most aren't rated below -70 C, but I know in the past I've seen sets used down to 1.6 K. (Wish I could remember what they were!) Does anyone have specific recommendations? Or general advice, plastic vs ceramic, etc? I've never purchased anything like this before, so I'm especially interested in carrier/socket pairings. (I guess they are never sold together...) Any advice appreciated. Thanks!