tent size

Hello Nature’s Gurus, I’m setting up a grow box for a 1x2x4 feet (30x60x120), I’m upgrading after 8 month to a bigger box. I don’t want to repurchase my equipment after changing the size. Can I set a 600w hps air cooled reflector for 1x2x4 (maybe dimmable).

Most people I'm guessing are going to say use the bigger one for flower as the plants will olny get bigger.. Tents : I have a 3*3 and one just shy of 5*3 Wich should be flowering tent? I would do the larger one but I'm considering keeping 4 moms and vegging in it. Plus I have veggies.. and I...