Hi
I believe you are seeking board development for DDR3 and DDR4 in the Stratix device?
We are unable to provide any board design support, but we can guide you for some reference material.
For the schematic, you can refer to the development kit material:
Devkit reference- https://www.intel.com/content/www/us/en/programmable/products/boards_and_kits/dev-kits/altera/kit-s10-fpga.html
Schematic- https://www.intel.com/content/dam/altera-www/global/en_US/support/boards-kits/stratix10/fpga/s10gx_pcie_devkit_revD.pdf
For board design, you may refer to DDR4 Board Design Guidelines chapter for the S10 EMIF UG.
https://www.intel.com/content/dam/www/programmable/us/en/pdfs/literature/hb/stratix-10/ug-s10-emi.pdf#page=231
hope this helps.