What ballast can i use with a dubble ended hps?

looking to make the switch to DE HPS. Originally I thought I could use my normal 240v digital ballast but after some research I'm not sure. I read something about using 400v ballast or one with an overdrive or something of the sort.

DE ballasts/lamps operate at about double the frequency of single ended digitals.
I personally went with hydrofarm phantom de but next time I think I'll check out what solis tek has to offer. I dropped about 8 bills on the ac/de hood, phantom ballast and ushio lamp so they aren't cheap.

Any info by chance on a actual 400 volt ballast to use with these? Obviously with 400v bring avalible where needed. Would this bring the amperage down a significant amount like switching from 120 to 240