In a 9x9 area with 4/1000 watters your looking at about 4600 lumens persqft. I think my math is right but if im wrong hopefully some will correct me. The closer to 5000 you get the better. So looks like enough light. Im not sure on Htg digital ballast (never owned one) but their magnetic ones are great for the price. Whatever you get remember to buy extra bulbs. With that being said, have you thought about using hps for veg and flower? It would be alot cheaper and itll leave you more money to get a good carbon filter or filters. I dont use those cause my room is way secluded so i dont know how big or many you will need. Sorry.
Those 1k lights are gonna throw out some heat so you are probably gonna need a dedicated ac. I do with 2/400s haha. But i know nothing about your setup. Hopefully you have thought about electricity. Thats gonna be alot of amps so hopefully you thought about how many circuits that room needs to run smoothly. Would hate for you to get everything and you cant run them cause of tripping breakers and things to that nature. Fire hazard being the most important. But you have probably thought about all of this already.
I have heard great things about phantom ballast. Out of my price range so i have never tried them. For bulbs i use hortilux eye. To be honest, I cant tell a major difference from the cheap htg ones for plant growth. Thats just my little 2 cents