Which Fan

I am going to be starting a grow with a few plants and a 250 or 400 watt hps. What size fan should i use? 2 choices from homedepot

8 In. 110VAC 500FM In-Line Duct Fan
or
6 In. 110VAC 250CFM In-Line Duct Fan

anyone have experience with these?
Are the loud or really noticeable?

Is a 400 watt hps too big for a 2.5x2.5x5

can anyone answer?

yes, those fans are not what your looking for .. google inline fans or centrfugial...vortex,can,etc... you want at least 200 cfm to vent a small grow space and light .. good luck soory i couldnt help to much