I would strongly recommend against using electronic ballasts unless you are growing in a legal climate.
I passed the AM radio test, but.. after a year of just snipping my coax line to avoid confrontation, over and over and over, the cable guy eventually came banging on my door to tell me he knew exactly
what I was doing, and that I was disrupting over 600 people with a 600w ballast. He was cool as f*ck and told me to shut down shop immediately before the field techs came to look for "wiring problems" with a sheriff, and also to switch to satellite, altogether.
If you insist on using electronic ballasts, I would first make sure that they aren't made in china. I doubt you'll find a chinese made e-ballast that passes fcc rfi standards. I would then shorten the leads from the ballasts to the hoods as much as humanly possible, probably even mounting the ballasts to the hoods, gavita style, and equip the leads with rfi ferrules. I would then make sure i didn't have any redundant wiring anywhere in my house, and also make sure that my light fixtures were nowhere near any coax, preferably even pulling all the coax out of my house in favor of fiberoptic or satellite.
Or.. just stick to magnetics.