I currently run a 3-axis home-build, and I have a 4th axis attachment. I use Rhinocam to generate my code, and Mach 3 to run it.
My cad/cam software runs around $2600, and Mach 3 (the most excellent controller for the price) runs around $150.
While the motors, drives, and controller can be had for cheap, software to create 5-axis Gcode is very cost-prohibitive for the hobbyist.
It is also difficult to cheaply create a 5-axis system rigid enough to tackle any kind of metal work, unless you are a machinist, resourceful, and able to do a lot of research on the mechanics/control issues on the 5-axis head.
I wish you the best of luck, but I do not expect you to meet your goals anywhere under $24,000 (for software, controller, drives, linear components, drive mechanisms, spindle, etc.)
Just my opinion.