The Aquateko Single Strand Nickel Titanium Bite wire is the best tieable wire I've ever used, the 35 pound test has a diameter of about 20 pound test nylon monofilament fishing line making it very difficult for the fish to see, it is my number one Bite Tippet for Muskies.
Available in 15 or 30 foot spools, the knots to use are not difficult t tie and complete instructions are on the back of each package! 15 or 30 foot spools also available in 25 pound test for ultra clear water or smaller fish.
Check out the Invisa Swivels also, I use them for a foolproof connection between the wire and the Mono Leader line.
If you're looking for a softer wire that still doesn't bend or kink, the 1x7 Braided version is very soft and supple, it is very tieable but in braided form for more movement throughout the entire bite tippet, the diameter is larger than the single strand but it ties a bit nicer.