I think the 1300, 996, and 998 would be the next likely candidates for customization (since they're made in the US). I would prefer the 1300, but I think the 998 would be more likely since they bear the least resemblance to the 574. With that being said, I would hope that the addition of a new model would not mean the removal of the 574. I think it's important to remember that these are the asian-made 574s seen everywhere. The shape and materials are head and shoulders above those. Regardless of the model, I think the greatest improvement which could be made is more freedom to customize the midsole and outsole, but I'm not holding my breath on this.