First, both liposuction and tummy tuck procedures are body contouring procedures, not weight loss procedures. Even in cases were there is a lot of skin to remove (such as a massive weight loss patient), the weight of the skin removed is surprisingly little (2-3kg or 5-7 lbs is really an impressive resection.) For liposuction, we consider "large volume" anything over 5 liters, which tends to be quite aggressive and a reasonable metabolic challenge for your body. I personally would not perform a combined tummy tuck and large volume liposuction due to the risks involved. Lets assume you did remove 5 L of lipo aspirate, which is 60% pure fat - so 3L. Fat is lighter than water, so you would have less than 3KG, or 7lbs.
You currently have a BMI of 31. If you are at your peak lifetime weight, you are not a good candidate for a tummy tuck. If you happen to have been very overweight (300+lbs) and now are 215 with very loose skin, a tummy tuck would be appropriate. (If you are currently at your peak, everything is very tight, and it is hard to "tighten" it more.)
Surgical weight loss (gastric band, bypass, etc) is generally suited for higher BMIs. At this stage, the best solution would be diet and exercise till you get within 10% of your goal weight, and then consider body contouring.