alpha cone 170 or 200

[foreverfortune]

hi all, im looking for some input.
considering our dollar is pretty much par and there is a 10% sale on the royal exclusive alpha cones.
i am considering upgrading my skimmer from my euro reef rc135 to either the 170 or 200 alpha cone.

my question is should i go with the alpha 170 rated for up to 200g or the alpha 200 which is rated for up to 300g price difference isnt too much.
my current tank is a 92g corner 20g sump. i would consider heavily stocked and with 120# of LR, so water volume should be considered.

i know ppl always suggest bigger the skimmer the better but would one rated for 3 times my tank be too big? would i have problems keeping up foam production considering my water volume? or would it be wiser to go with the smaller skimmer and have it work a little harder?

thanks for the input