Unfortunately I can't control how long a Shipment needs. I usually ship these with Priority (the highest tier I can book) on the next work day.
You just have to activate the pSRAM in the make menuconfig. More is not needed! The compiler then choses automatically what it places in the internal and external RAM. Please reefer to the "How can I use this pSRAM?" Section on the product page.
If you need more Informations/Documentation I'm always there to get your Questions answered.