Sigma 18-200 or Tokina 12-24 for indoor group photographs

I have invited couple of families for dinner. I will be photographing using my Canon EOS500D, Sigma 18-200, Tokina 12-24 & Canon 50 1.4. (& external Sigma flash by bouncing from ceiling)
I will be taking number of photos in 20-35 mm focal range. I request experienced forum members to advise to wheather I should use Tokina in 20-24 range or Sigma in 20-35 range. Which one will give higher IQ. In this focal range, IS is not an issue even if I will be hand holding camera.
Thanking in advance.

at 20-35mm won't there bit some deal of distortion?

tokina is very nice, and i guess your 50 1.4 is too long?

i have a sigma 18-200 and the edge sharpness isnt that great. id go for the tokina.

If sharpness is a major concern AND the 50mm too narrow.....then it seems like your choice is simple -- go with the Tokina!

I am interested to get good sharp pictures including good peppy color reproduction as all ladies & children will be dressed colorfully & brightly.