Used scope many years ago. Some of you might remember me

I'm toying with the idea of getting a pulsar 1 card with adat ports and having that between my A/D converter and my RME adat inputs. Simply to use the pulsar1 as a way of getting zero latency monitoring with effects on.
Then the old problem arises: PCI!
I want to use my existing computer that has no pci ports.
Ideally I would insert a pci to pcie adapter into a pcie slot and from there, pull a pci flex cable down to an available slot in my chassis and install the pulsar1 there.
Is there such a solution? All the solutions I find, result in he cards being to "high" because they have to sit on top of an adapter card.
Come to think of it there is no space in my computer case. Might have to make an external solution. But currently i'm interested in electronics that actually work for this. Then I can always find an external case.
Any known good solutions?
Thanks!
