I don't have the same size machine (I have the 50W with a 500x300mm bed) so I'm not sure what your cfm requirements are, but I went with this fan, and it seems to work well.
I have this one: [https://www.amazon.com/dp/B07GB8PD7M/ref=cm_sw_r_cp_api_i_U7YBDb3GT5A03](http://) It’s super quiet and seems to work well.
Same machine, and same problem... I picked up one of these and it's been a much better experience. I know that one isn't available anymore, but I thought I'd give you a comparison to gauge the right CFM.