My tent will be 2 x 2 x 5 so I'm assuming the 4" vortex is more than enough for four square feet. I do like that day/night controller. Thanks for the links.
2'x2'x5'= 20 cubic feet
You want at least 5x air turnover per hour to maintain adequate airflow in your grow area and will require at least a 100 CFM inline fan. A a Vortex Inline Fan 4 inch 175CFM should work well to exhaust your grow area.