Those fans arn't really made to do that job, though depending on your container size, a few of them WILL get it done nicely. Just 1 is testing it IMO. What you really want is a centrifugal fan; 300+CFM, and made to overcome static pressure; loud and overkill mostly. The most well respect brand for quietness is Can-Fan.

But only 8GPUs you should be fine without that. Keep your gpu box as small as you can, another duct booster and you should be fine.