You could save yourself a buncha time by using my
FetishNightfall set as a foundation for yours. Its a complete overhaul of the entire UI specifically designed to be easily reskinned and was built to resist breakage when SOE changes their stuff. Probly 90% of what you want changed would only require tweaking the images and FetishStyles.xml.
This would also get you all the extra features already included in the Fetish foundation.
I encourage folks to reuse my stuff, all I ask is that you give credit if you do