Ok, the thread appears to be well-aged ... anyway: I'll add my personal recipe here because I consider it very flexible and adequately unfancy - as requested.
Basic material: enameled wire with an additional insulation, in my case ETFE, because I did not find PTFE. If you stay below 0.5 or 0.6 mm diameter, any skin effect should be no issue.
Cut to lenght as many sections as needed for your required application, add some 10 - 15 % extra length.
Divide into 4 equal bundles and tie these together.
Combine those 4 bundles to a tight braid.
4 bundles give you free choice whether to biwire or not.
Apply bananas or whatever of your choice and finalise with an unfancy cable sleeve (as requested ).
Thats it - just add as many wire lenghts per bundle as you think is appropriate for your planned cross section.
There's a spare reel left? Don't forget the internal wiring of your speakers - might worth a try. My Tannoys benefitted a lot.
BTW: for some odd reason I prefer pure copper, not tinned or silvered.