My 35/4.5 Apo-Grandy is rectilinear. But the camera has to be level and the back has to be parallel to the subject.
It is the shortest lens that covers 2x3, R'stock does and doesn't recommend it for 6x12. Yes, a center filter is essential, I've done the same shot with and without. You want a CF.
My 35 is too wide for many situations, but when I need what it does there's no substitute.
Depending on the format you shoot and prices when you shop, you may be better of with a 47/5.6 Super Angulon XL. It has more coverage than the 45 Apo-Grandy.