hmmm....

I'd go tent with cool tube and then inline fan to cool ducting. here like this. very crude but you'll get the idea.

View attachment 2481971

so have the fan and filter outside of the tent?

If you want or you can go filter>fan>light>out of tent. Really whatever works best for you. What works for me may not work for you.

yea i would need to have everything on the inside. Oh and how close can the light be from the top of the plants (600w+cooltube)

If you can keep your tube cool then you can keep it within 6-10" don't get to close or you will bleach your plants.

oh ok, how tall should my cab be?

I wouldn't go anything under 5' and that wont allow you to grow any sativa's but you can upgrade in the future, but I'd start with at least 5'.

i figured maybe 6' but im not sure. Is it safe to have the ballast in the grow tent or should it be somewhere outside the tent?

If you have proper ventilation you can keep it in the tent no problems.