question about a-arm lengths

[400EXracer74]

on a-arms when some say plus 3 and some say plus 2 are they really different or are the plus 3s +2+1 or is that just 3 different sizes available?

[450robot]

plus 2 is 2 inches wider, plus 3 is 3 inches wider

plus 2+1 is 2 inches wider, and 1 inch farther foward than stock arms

[400EXracer74]

which one would be the best setup for an 05 450R