These two procedures differ in what they target: Liposuction targets excess fat and the Mini Tummy Tuck targets excess skin below the belly button. These two procedures may be done at the same time, but the Mini Tummy Tuck can also be done later on, if you desire. If you have good skin elasticity and the excess skin is small in amount, perhaps you would feel more comfortable waiting until after Liposuction to see if the Mini Tummy Tuck would be beneficial in order for you to achieve your goals.
Factors such as the skin quality, stretch marks, the looseness of the mid line rectus fascia, and the amount of fat within the flap should be carefully considered in making your decision. Discuss these things with your surgeon to decide the best course of action tailored to your specific needs that will offer an outcome you can be happy with.