I have servers with 8 tuners, either TBS 6985/ TBS6905 quad-tuner cards for DVB-S(2) and the TBS 6209 DVB-C octa-tuner card that run streamdev servers really great. So, 2 quad-cards or 1 octa-card. None of them do have any CAM slots but they do work pretty good.
* either 2 Cards x 4 tuners DVB-S(2) or even 1 Card x 8 tuners DVB-C/DVB-T(2)
* works very well under openSUSE and Debian, streaming literally hundreds of active Radio streams in parallel from one box with 2 DVB-S(2) Tuner cards!
* Pretty expensive!
* You always have to compile and link the module drivers into any new kernel version (dough!)
Not exactly the exact answer to your question, but maybe that also would be an option to you?