Note that WoWEquip does not, intentionally, include your base stats (as these depend on race, class, and level and compiling a complete database of each combination's base stats would be an enormous undertaking)
Umm, why? We don't need an option to change our race or level to see what we our stats would be as a level 1 gnome shaman in T6 and sunwell pally gear, we're just seeing how a gear change would affect our current stats for our current race and class. Since you DO track what the change is, why not instead of displaying the "gear only" contribution, just pull the number for that stat conveniently pre-calculated for you on the character page and just apply the change to that, displaying that number.
KISS (no offense :P)