Extended TT with or without an FDL? (Photos)

 Looks to me like you would be a candidate for an extended abdominoplasty and you would not require any vertical incision because I don’t see a lot of horizontal laxity at the upper part of your abdomen.
The only question is to whether to do a circumferential versus just an extended tummy tuck but it’s hard to tell from the photos. One thing to keep in mind is that you can always start with an extended tummy tuck and then if you were unhappy in a year or so with the posterior aspect, or the back of your body with excess skin, you can always have a completion circumferential belt lipectomy, meaning you can just do the back part of the operation at the second setting. But I definitely  do not see any evidence from your photos that you would need to have a vertical scar. 

You most definitely have a circumferential excess of lose skin...I can see the roll extending around to your backside which is very common after you have lost 90 or more pounds. For that reason, I feel the LBL is a must.
You will have a lot nicer waist contour and less excess when you bend forward of you also do the vertical incision or FDL.  You need to decide if that extra scar and possible slower healing is worth the improved shape.

Judging from your pics, you have the appearance of someone who has undergone massive weight loss with gastric bypass surgery.  Usually in this scenario there is significantly more loose redundant abdominal skin to have to deal with than our typical tummy tuck patient.  Most traditional tummy tuck patients have redundant skin along vertical axis, and hence the traditional tummy tuck with the low transverse abdominal scar (bikini line) is sufficient to eliminate this excess with just that scar.  Massive weight loss patients usually also have excess loose skin along the horizontal axis as well, which cannot be addressed adequately with just the transverse scar.  Hence the vertical mid- line abdominal scar can be utilized to remove skin along the horizontal axis (to tighten the skin more circumferentialy arond the waistline to give you tighter skin and accentuate your hourglass figure).  The FDL scar is a lot more visible and there is greater risks for wound healing issues and numbness so that is the downside but it might be worth it if you desire maximal skin tightening and contouring of your waistline.  I would ask to see your surgeons' before and after pics of their traditional vs. FDL tummy tucks to see how the results differ and how the patients looked like before surgery that would require the FDL component.  Best wishes.