I'm not sure of the preorder process at Sony Store, but I think it might be the same as game retail stores. The standard small deposit is required to confirm order (Or I might be wrong, maybe Sony Store require full payment upfront etc. Have to wait & see)
Back in 2013, I preorder PS4 from the game store at AMK Hub, and purchase it on launch day in December. I remember $50 deposit is required in advance to secure a set. PS4 $639 sold out fast, only left the PS4 + Battlefield 4/Killzone bundle at $699. If I remember correctly, I think there's also a PS4 + Camera bundle.
Hoping to see a PS5 + Spider-Man: Miles Morales bundle this time around.