HIDHUT.com
Their brand of digital Ballasts work without problems. Several years and counting.
$139 for a reflector, digital ballast and bulb for 400 watt HPS. Just look at their combo setups.
Their stuff is also new, I know some of the sites sell refurbished junk which usually means they too hi bays out of a warehouse and repainted them.
If you order from HTG stay away from the Digital Greenhouse Brand, the bulbs usually burn out within 2 weeks unless you get a good one, they will replace it but you are looking at 3 weeks of downtime unless you buy a couple extra.
Also it is a good idea to buy ome Never Sieze and put a little dab on the threads of HID bulbs, if they ever do corrode together (Bulb & Socket) the bulb always ends up broken and you'll be trying to unthread a stuck bulb with broken glass and it isn' safe......