I wouldn't think you'd have much problem with the boys lifting their legs once the initial adjustment period is over, and they make belly bands for that. That being said, there is nothing wrong with getting two girls. I think it's more about personality than sex, especially when they're fixed. We have tile and Jake doesn't have a problem unless he's going really fast. I would be prepared to temporarily use rugs if they're uncomfortable at first. We have one guy only and both work all day, and I no longer feel much guilt because if we come home early you can tell we woke him up Again though, your plan sounds good too.