They are fine turnbuckles. Johnson Marine
also makes good hardware
, as does Navtec. Rigging Only
has great prices on quality hardware
, and they're very knowledgeable, friendly and willing to answer questions and help you with rigging
When we rerigged, we purchased all of our wire and terminals from them; we didn't need turnbuckles though. You may also keep your eye on ebay - Merriman and Wilcox-Critten bronze turnbuckles show up in lots there for great prices, too.