Is there a superior suture material and technique for better upper blepharoplasty results?

Sutures dont make a long term difference in terms of scarring. Absorbable sutures tend to come out/break a little easier so you have to more careful with touching and rubbing your eye. They are often more comfortable when lubricated so most common lo y are used on the lower eyelids so the eye isn't as irritated. However, surgeon preference is the most common deciding factor. This shouldn't be the issue you are too worried about.

The most important factor in achieving the optimal scar after blepharoplasty (or any other procedure) is the skill of the surgeon and his or her attention to detail.  The particular suture used or the closure technique utilized is of limited importance.  However, timing for suture removal may affect the outcome; sutures left in place too long could leave marks.  Some dissolvable sutures may not "fall out" early enough and could leave the track marks I am referring to.

On patient with thin skin, typically Northern European background, a buried running suture can work well. For other ethnicities with somewhat thicker skin, I prefer a combination of interrupted and running sutures. Interrupted sutures give a more precise closure but are tedious (and tender) to remove, so a running is combined to reduce the need for interrupteds that run full length.

Surgeons often have their preferred method and suture type when closing the eyelid. The specific suture material probably doesn't make a huge difference and once the eyelid heals the scar will likely look very similar regardless of the suture material used. A smaller gauge is typically preferred compared with a thicker gauge given how thin the eyelid skin is.I typically prefer using a very thin non-absorbing suture that is removed about 1 week after surgery. In my hands this method works great.More important for your upper lid results is the design of the skin excision and wound closure technique rather than the specific suture used.You can learn more about blepharoplasty surgery at my web reference link below.

Choose a very experienced surgeon who gives results you like in eyelids like yours! The suture type makes no real difference.

I am not saying it is not important but the diagnosis of the actual issues, the design of the blepharoplasty, and the repair of eyelid structure are much, much more important. Many surgeons take pride in placing a subcuticular skin closure in the mistaken belief that it makes a big difference. These surgeons often ignore the correction of deeper structures in the eyelid. Makes no sense. Don't talk yourself into focusing on something that is not that important. You need real structure in your eyelids. You have loose crepey upper eyelid skin. I would recommend an anchor blepharplasty and preservation of your upper eyelid fold and volume. You do not need a forehead lift.

The technique for suturing after upper blepharoplasty will be dependent on the preference of the surgeon performing the procedure.  There are multiple different ways that the upper eyelids can be closed after surgery, and each surgeon is going to use the technique that they feel works the best.  My personal preference is to use a running, subcuticular closure.  

In our practice, we usually use very fast disolving absorbable stitches  that do not require removal. the type of sutures you  use doesn't really impact as results very much

The type of suture used or style of suture is not as important as the surgical technique and strategy to improve the upper eye aesthetic. 
The most important principles for optimal scar healing are
-surgical technique
-no tension on the surgical incision / closure
-removal of suture 5-7 days after surgery
-patient compliance with postoperative care
Hope this helps! 

Your research on suture technique for upper blepharoplasty is the last thing you should be researching. Instead, you should be looking at the surgeon and his or her experience in treating problems like yours and whether you like the results shown. All the other parts of the procedure, diagnosis, treatment of the deep structures and treatment of any other areas impacting the area are all more important. If the surgeon does all these well, you can almost be assured that the method used for closure will be excellent.