Hi,
Thank you for your interest in NXP Semiconductor products,
i.MX 8 QuadXPlus supports PCIe in NXP BSP, both RC and EP roles but DMA transfers, you'd need to create a TC for it.
For HW, we cannot offer the material to perform the test; nor between i.MX nor i.MX to PC. You can use a FPC cable and optionally an adapter for PCIe/miniPCIe connectors.
Regards