I just bought some COB's from Timber and they havn't got here yet. The heatsink was backordered and took an extra week. I don't care though. I researched all the cobs I could find for year before I bought any. There are no better lights than Timber and Autocob. They are all hand built, to order, and use only top of line parts. Both companies will help you out picking them by email or phone, and will work with you if you need it for installation, or have a return or something.
heres the link to the ones I got.
http://timbergrowlights.com/400-watt-vero29-v7-4-cob-grow-light-kit/
final cost was 520.00 shipped, with reflectors and ratchet straps. I figured the math on it, it will pay for itself in 6 months of usage.