I've used this 6-core cable from B & Q. It's tinned and has the right number of cores for R+/R-, T+/T- , +ve and -ve. It's quite thin so probably not suitable for anything power hungry.
The 2 offerings I have are Maretrons supper wizzy stuff, generally used for 2K which I have to use on their installs or general serial cable from RS for most other stuff. I also use stranded alarm cable heavily on the big vessels for the PT sensors, that'd hold up as good as anything for domestic 0183.
I use Alpha Wire 2466C for bi-directional differential signalling (two individually shielded twisted pairs) and Alpha Wire 2461C for unidirectional connections (single twisted pair). Thin and flexible with tinned conductors with relatively large cross-sections (useful also for e.g. carrying power + data). Come in around £1/meter on 30m reels from Rapid Electronics.