Is a hair transplant better or forehead reduction in my case, having a widows peak? (photo)

You can lower your hairline with surgery but to understand how it may actually look or to understand realistic expectations, you need to see a doctor in person and have this conversation.
Forehead reduction surgery or hair grafting transplant can both lower your hairline.  It would be in your interest to have a consultation with a doctor and understand your risks and benefits of each surgery.  It would not be fair to suggest one or the other option without an examination or understanding your specific goals. There are issues of scarring, shock hair loss, hairline shape, and many other factors that must be understood.One risk is that forehead reduction surgery leaves a scar on the hairline no matter which surgeon or type of surgery performed. However, most of these scars are not as noticeable depending on how the individual heals. One limitation is that it does not round out the face (temple corners).
Hair transplant surgery may be an option for a forehead reduction. Hair transplant surgery does not leave a scar on the forehead. It actually can give you a natural and soft hair line as well as rounding of the temple corners. Like all cosmetic surgery, how "natural" this may look depend on the artistry of the surgeon. Hair transplant surgery limitation is that the results are not immediate and the growth will not be as "full" as a forehead reduction surgery.
You can see an example of a hair transplant surgery in the video below.

There are a variety of factors that determine relatively candidacy for hairline lowering by surgery (also called surgical hairline advancement (SHA) or forehead reduction surgery) versus hair grafting-  you really want to find a doctor who specializes in both.  The SHA requires a relatively stable frontal hairline, and good to very good scalp laxity.  In my practice, I typically perform 2 SHAs every week while I do usually twice that many hairline grafting procedures in women, reflecting the candidacy as well as desire for the two different procedures. 

A hair transplant is the only option that allow you to keep your widows peak in its natural shape. Forehead reduction leave a line of scar in front that you still need to transplant hair in front of it to hide it and create a more natural look on your hairline.

Surgical hairline advancement will leave more scarring but the scarring can be covered with hair transplantation. I prefer hairline advancement with grafting because if done properly will give the most natural result. No matter what direction you take do your research well and choose your surgeon carefully.

You are asking about forehead reduction surgery of hair transplant reduction?  When I look at a person for this type of choice, I look to the corner hairline, which is your case is in good shape with no hair loss, so a forehead reduction surgery should work reasonably well.  Ask the surgeon about preserving the widow's peak. If he can't then a hair transplant approach may be better. See below