remember that the aquarium trade is built on lies and ignorance
. Almost everything we use in the hobby is used elsewhere and is cheaper. Thats why an individual with a keen eye can really save some cash if they know what they are doing and know what they are looking for.
Granted some of the items are reef specific but even then - given the opportunity everyone in this hobby thinks they can double the price and put "safe for aquariums" on the fine print.
I dont know much about Halides but if the socket and ballast wattage match some of the bulbs you want to use i see no reason why you can't save yourself a few hundred dollars
. Keep us updated - would love to see those installed