Hobbywing is the OEM of Speed Passion products. I hear that SP does their own programming, but HW stuff works very well. They have an EZRun line of sensorless systems, and XERun line of sensored, both are available with 17.5T motors. Hobbypartz.com has the best prices and shipping on Hobbywing, but they dont carry the whole lineup, you can usually find the rest on Ebay.
www.hobbywing.com
www.hobbypartz.com