The two gray slots are PCI the others are PCIe. There are PCI 4 port SATA cards available.
Semlos 4 Ports PCI Sata Internal Raid Controller Card Sil3114 Chipset 013577 with 2 Sata Cables
Would I have to buy 2 of these or can I keep the pci-e card that I have and keep the 4 hard drives connected to it and buy just one of these pci cards and connect 4 hard drives to it? Would they interfere with each other? (probably a very dumb question but I needed to ask)