May I ask, why 30mm main tube? With 30mm tube you get more moa adjustment then a 1" tube. But with proper mounting system you should do just fine. Where you get the more light gathering capability is the larger objective bell. 30mm scope generally are heavier then a 1" scope.
Get the 1" tube model. As mentioned the only real advantage the 30mm has is more internal correction. The 1" tube scopes gather just as much light as the 30mm ones, given the same lens sizes, and the 1" scopes are a bit lighter. Every once-in-a-while a smidgen faster handling is a good thing.
