my first grow, but need help getting started.

Hey everyone, this is my first post. i will be attempting to grow indoors with soil.
i will be building a grow box that is 3 feet wide and 5 feet tall. i was planning on doing the scrog method unless you think otherwise. i will be getting a 400w HPS and a 400w MH (one ballast and hood that is compatable with both) i was going to start 18/6 with the mh from seedlings and switch to the 400w HPS for flowering. it will be an enclosed box. the light hood has a glass cover on it with a side vent that i will lead out of the box, and i will put a hole on the side of the box for a fan. i plan on growing 1-2 plants depending on what you recomend for this amount of space and if the light is powerful enough or if it too powerfull let me know, im yet to purchase this, i want to have evrything planned out before i do this. I am yet to choose the strain i want to grow, should i grow a sativa or indica or what type of mix for scrog? should i look for tall plants to fill screen well or should i be looking at medium or short plants. Any recommended strains would be great help, i also would like to get a nice yield (i know i should not expect too much for a first grow but am i crazy to aim at 1-2 o dried?), if that affects your input on strains.

also i was going to make a homemade carbon filter i saw here if you all think it will help.

i would like advice on everything, and i have not a single clue about nutes which is where i need most help on. what should i get, and should i get extra things like bud candy (as ive seen a lot of people recomend this product), but keep in mind im not trying to spend a lot of money on nutes.

if im missing anything in this plan or if you would suggest me do something different or add something please let me know.

Is this an overall decent set up or not really?
Thanks in advance!

Sounds like you have it under control man. Good stuff.

Yep sounds good. I have a 250w switchable HID and its keeping three plants very happy (it was keeping 4 plants happy until I pulled the male)! I wanted to get the 400w but with my limited grow area I chose the 250w due to the fact they give out a lot of heat. I got the switchable too - I don't regret getting a switchable but now that I'm into flowering I plan on doing a perpetual harvest which means two cabinets one with an MH or Fluros and one with an HPS. Still the switchable is nice 'cos I am able to use the MH bulb in it during the transition into and out of flowering.

Your seedlings won't need nutes for a couple of weeks. I strongly suggest foxfarm ocean forest soil. I suggest the foxfarm nutes too: Big Bud, Grow Big and Tiger Bloom -- Big Bud is used through out the grow, Grow big is used in vegging and Tiger bloom is used in flowering (that is to say, roughly, a mixture of all three is used in flowering when following the foxfarm schedule...and you won't need any nutes for the first few weeks or your grow, a month if you're growing in foxfarm ocean forest soil.)

is it cool that i use the mh from seedlings, im trying not to waste any more money than i need to, and if you know where to get better prices let me know, the fox farm trio nutes is $35 and the fox farm ocean forest soild is $21, my lights, with an air cooled hood is $240, and i was going to buy a 6 inch fan for $15 and the DIY carbon filter on this website for $25. Grand Total so far is $336. is this a good deal?

Any help on choosing the strain would be great, imj looking for a high yield so i thought scrog would help, or should i grow normal and top the plant. also if i scrog could i still top the plant?