Seeds are from Dutch Passion, Auto Mazar&Think Different.:tiphat:
Seeds are very good choice as well as lighting.
You will cheaply get the best result if you buy 400 W MH bulb and use it at 300W then in flowering, you would change for 600W HPS run on 600 W. Your balast supports 400w and 600w bulbs.
Have in mind that you will have to change your bulbs regularely for the best results and you will wear out both anyway. If you buy two, they will simply last longer and they are not expencive at all. Remember that you are buying very good light so buy the best bulbs too, no matter if one costs 2 grams of dried buds more. 2 grams buds can be easily paid out during better quality of equipment. And makes your grow better overall what means more juicy buds.
If you grow properly, you will have your investment in MH bulb paid out in the very first grow.
I started four of my TD under LEDs and then moved them under HPS yet in vegetative stage and there is some unnecessary stretch and plants do not have so rich structure I would like them to have. But no problem at all, I am just talking about what is the best and notwhat works somehow. HPS works somehow also in veg stage but it is far better if yo do not make yourself limits that can be avoided.
If this is your first grow you will make yourself many troubles, I am sure, and you do not need to make things worse where not necessary.