and want over 100 lumens/W! 
http://www.greenbuildingadvisor.com/blogs/dept/guest-blogs/led-filament-bulbs
(broken link removed)
apparently they get higher lumens by emitting in all directions, and get good cooling by filling the glass builbs with Helium gas.

http://www.greenbuildingadvisor.com/blogs/dept/guest-blogs/led-filament-bulbs
(broken link removed)
apparently they get higher lumens by emitting in all directions, and get good cooling by filling the glass builbs with Helium gas.