Again, it is anyones opinion. For 12k or 14k, Seems like Coral Vue and Hamilton are most common. For 10k and 20k most seem to like Coral Vue, XM, Ushio and Radium.
Check this link out. If you read RC their are more expensive bulbs out there and there is a decent price difference on the bulbs listed. I use Coral Vue 10k and just purchased CV 14k bulbs. Some people consider these cheap. I like them and they have given me good growth. I would stay away from a no-name ebay bulb unles you want to try it out.
Sunburst are pretty cheap too but not sure about longevity.
Good luck, sorry I cant help more. CV is all I have ever used but I did research quite a bit on 14k bulbs. I chose CV over Hamilton because they were cheaper.
*180 gal Display, 100 gal basement sump, 33 gal refugium, 3x250 MH, 2x160 VHO actinics, zoos, some softies, LPS & lots of acros and other SPS.
*100 gal prop tank plumbed into main system w/ 2x96 PC lights and 1x150 MH,