Lipo or Tummy Tuck with an Upside-down T?

Without a picture it is hard to give specific advice. With abodminoplasty, there are many options. The inverted or up-side-down T is only necessary if there is not enough loose skin between your belly button and the low incision. It is rarely necessary to do this. In most cases, this skin can be excised (removed) without much difficult. Good luck with your surgery.

You are 5'3'' and weigh 110 pounds, so I assume your problem is not a big abdomen with a lot of fat.
I assume what you want is tight skin, but not having a lot of excess skin, the surgeon is worried the skin over the belly button will not reach all the way to the pubis.
Ask him how long the vertical scar will be. In my experience, I have found that 99% of the time, even when the skin does not reach the pubis, using the skin bordering the umbilicus as the "vertical element" of the upside down "T" is more than enough. This is only about an inch long, and can be excised later when the tissues relax.
The amount of tightening you will get from Vaser, or Laser lipo and a Mini Tummy Tuck will not make you happy. I know from experience, mine and others.

There are a couple of things to consider here. Usually, when we refer to the upside down T scar, it is a vertical line extending all the way from the navel to the horizontal scar which is low. This is done only for massive weight loss patients, which doesn't sound like you. The other version is a short, vertically oriented scar from closing the hole where the belly button was. This occurs because most often we remove all of the skin between the navel and the pubic area, which means that the skin above the belly button has to stretch all the way down to cover it. If this skin won't stretch enough, the the other alternative is to have the horizontal scar too high. In this instance, a short vertical T is a good tradeoff.
One thing to be wary of is claims about skin tightening from all of the various technologies with liposuction (smart, cool, laser, vaser, etc.) None of these does as much as a tummy tuck so it that is what you need there are no short cuts.