okay, just three(3) quick points:
1. "guys" can be found in both M-WCD and AHD in the sense of "persons", although it is listed as "informal" -- what does this mean? it means that usage is widespread and has been for some years.
2. "ladies" is the counterpart for "gentlemen"; this only works well for formal occasions.
3. "you people" sounds too much like a drill sargeant in a good mood.
4. your other suggestions sound very forced, when what we're wanting is very informal.

oops, that was four(4) things. so tsu-me.