Breeding size questions

Ok I have the option of getting a ten inch female burgundy Goliath or 7 inch female. I have a adult male but may be past his time and a sub adult male my question is what would be the best option 10 inch female or 7 inch female supposedly the 10 inch female is in premolt I was just worried a spider that size would have a very short life span and not be able to breed considering the sub adult male has a molt or two to go yet.