Conditional library inclusion

Maybe I didn't express properly, I'm not confused about the code.
I am confused about where files are located.

Because it's not the same to do

#include "SoftwareSerial.h"

Than

#include <SoftwareSerial.h>

My question is, where should I keep my SoftwareSerial files and whether it's possible to avoid using them locally like I have been doing. I would much prefer having just one copy of each flavor that installs with my lib.h lib.cpp files. Right now, the only way to get the desired behavior is by having a folder that looks like

version a

whatever_a.ino
lib.cpp
lib.h
SoftwareSerial.h // mind this is different from <SoftwareSerial.h>
SoftwareSerial.cpp // mind this is different from <SoftwareSerial.cpp>

version b

whatever_b.ino
lib.cpp
lib.h
SoftwareSerial.h // mind this is different from version a
SoftwareSerial.cpp //mind this is different from version a

I would rather have a folder that looks

whatever_a.ino

With

#define USE_VERSION_A
#include <lib.h>