Here is what i did: When i needed to change T5HO bulbs i got 4 strips of 50/50 high power Blue LEDs. They are 470nm (same as actinics).
Colors POP and corals like it in general. Its been 3 month now. It looks good, relatively cheep even including power transformer (120 to 12v) its comparable to a cost of new T5 bulbs. The only one thing is that you need to mount them on your reflector or any other metallic material to keep them cool or they will not last as long if overheated.
http://www.canreef.com/vbulletin/sho...t=87189&page=4
scroll down for pictures of the fixture.
Read the description in the thread of the exact cost of these and also where to buy from. i don't know if he can ship it though.
Sea Horse Fanatic was first one to buy these blue LED's so may be you can PM him also for his input.