Going through similar thoughts now...
Also have 6x drivers only 600ma though.
Plan is to hook them up to 6x 1818 and thinking i will go for active cooling, and then prepare to upgrade the drivers, when i got more money
... I found price difference between 1812 and 1818 to be almost non existing. I Saw someone who got a quote on 1825 from kingbrite at 10.5usd, will be about twice that for 1818 from Europa, but alot easier when a cob is not working or they send the wrong cobs...
Also have 6x drivers only 600ma though.
Plan is to hook them up to 6x 1818 and thinking i will go for active cooling, and then prepare to upgrade the drivers, when i got more money