Other than the Central Hobbies carbon fiber stuff, my other favorite is the Hangar 9 Pro Link Titanium turnbuckles.

They are more expensive but they are LIGHT and allow you to make very fine adjustments without disassembling the pushrod assembly if you are using ball links. Another limiting factor is the length. But they make them up to at least 4 1/2" if not more.

http://www.horizonhobby.com/Products...ProdID=HAN3553