Richard,
Welcome to my world with regards to suppliers of anything! Last year, someone on this forum recommended MPJA www.mpja.com) out of Florida. I bought various doo-dads off of them to make my DIY power packs and throttles. After a year of service, and this despite my abysmal soldering skills, all the parts are holding up fine. For another project, I had to go to some random vendor selling via Amazon, and it worked fine. The key for both sources was to wait until I had a big enough order to make the shipping worth my dollar, which did delay both projects.
Eric