You've come a long way and the room is looking good. If I were in your shoes, I'd go with what I already own and run the two 600w fixtures. I was concerned about the light coming through the garage door cracks but, the film should block most of that.
Might have some noise issues, doubtful, but if you do, you can buy some insulation board and cover the garage door opening. The insulation board would also help with temps and stealth of the heat sigs. from the street. I would also disconnect the lock arms coming from the outside garage door handle and run bolts through the roller channels to absolutely prevent any movement of that door and access from outside.
I like what I see and I'm jealous of the large grow area. Nice progress!