I have purchased Sowa arbors through Suncoast Industries of Florida, Whoever they source from I find their product lines to be very good quality at reasonable price points. I would recommend them, they do not sell directly to the public so would need to go through one of their distributors. I recently contacted Sowa about parts for my Narex boring head, but he to purchase the parts through Suncoast. Also depends on the type of collet you are looking for, so something like 5C if you need a full set then QMT, KBC or Shars have decent Chinese brands. Vertex collets are made in Taiwan and have a bit better fit and finish. Lyndex 5C are way to expensive and there specs are no better than the other brands. R8 I have not had good results using the cheaper generic sets, you only need a limited number of sizes so maybe Lyndex, Vertex, Iscar/ETM, or similar quality is worth a bit more expense.