Furuno. They're the last company standing - every other brand has since been purchased by someone else. To the best of my knowledge, they are the only brand allowing local service (in other words, they'll reimburse the shop without question or haggling). If you want any other brand repaired, plan on shipping it off. Regards transducers, you'll see many more 600W units than the 1000W due to price alone - respectively about $250 and $850. One nice feature about Furuno's transducers is that they're tilted internally so you don't need an angled fairing block (a flat block is needed, of course). Incidentally, we're talking about a big hole for the 600W and a really big hole for the 1000W. Money well spent as the stuff never seems to break.