Inductor choice for passive filter
For a 50 Ohm filter, the 2.2mH choke you linked has 7.5Ohm "may" shift a breakpoint up 1 order of magnitude near 1kHz, resulting in 20dB less attenuation below that.   Other chokes are available (at higher current ratings not needed) with 0.25 Ohm that will work better for low-frequency rejection.  https://uk.farnell.com/hammond/1537n/rf-choke-500uh-5-3-2a-axial/dp/2759969

BTW you can get a perfectly flat Bessel PB response with a 50 Ohm load, albeit -6dB unless you  buffer the input to ~ 0 Ohms
Here's a simple 4th order approximation.

You could also make it an 8th order active filter. with a quad OA with no chokes.