Will I have nice results from upper Blepharoplasty or do I need a unilateral pretrichial brow lift? (Photo)

It is difficult to say with a single photo and no physical exam. It does appear that your brows are low and you do have excess upper eyelid skin. I cannot see your hairline and unless it is very high I would not suggest a pretrichial browlift. There are other approaches to your brows.

Generally, when patients want eye surgery, we often recommend an eyebrow lift (forehead lift) together.Especially if the distance between your eyes and eyebrows appears narrow in photos, performing eye surgery or skin incisions may bring your eyes and eyebrows closer, which can result in an unnatural appearance.
By lifting the eyebrows upward through the forehead lift, the skin is also pulled up, creating more space between the eyes and eyebrows, making the eyes look clearer and more refreshed.
Depending on the current width of your forehead, a forehead reduction surgery might also be recommended. In some cases, a forehead lift alone can eliminate the need for separate eye surgery.