Supersoil is a good choice.
I was just remembering my first grow the other day. I had been reading this book
over and over for weeks, saved up a little money to buy shoplights, plant bulbs, plastic pots, bone meal, blood meal, kelp, bat guano, dirt in a bag, perlite and a small fan for my 2 × 6 foot closet, Never pHed my water, flooded my saucers with standing water, did feed them ever. I don't even know how I got to harvest but I did, four months later, i had the best Damn quarter oz ever, lol . Cannabis growing has come a long way especially with the information on the Internet and the quality of your return will be worth your initial investment, you will be soooooooo thankful you have the extra room and the means to acquire this and that trinket. Point is you can get it done with the minimum but why settle if you've got the room.
My nemesis in hauling and storing water, 5-7 gallon jugs in a 7×8 grow room not to mention everything else, oh and room for plants, If you only knew my small room problem.
I look forward to you grow
Dude