The passenger side frame rail mount bracket is the main difference in the mounting on B series swaps,but on K swaps,this bracket needs to be chopped off no matter the model you start with.
Youll need the 5 speed pedal assembly,clutch master cylinder and hard lines.The firewall already has a spot on it for the clutch m/c to be mounted.
Other than that,the swap will be the same.The rsx swap will require you to replace most of the parts that would be needed to convert to manual from auto.
Just as a reference,youd need these parts to swap to a manual transmission on a B or D series:
5 speed tranny w/slave cylinder
manual pedal assembly
clutch,flywheel
clutch master cylinder with bmounting brakcet and fluid lines
5 speed pass. frame rail mount bracket
5 speed mounts for tranny
5 speed ecu
wiring of reverse lights and bypass of of starter cable from auto shifter harness.