About the scar:
Circumcision ALWAYS leaves an scar as any other surgical procedure. In some people are more visible than in others. Depending on the
melanin in the skin it will leave a darker or lighter tone, or both.
Melanin is the pigment that gives skin colour, so in this particular topic, the lighter the skin the most unnoticeable pigmentation, olive skin (latino's) tend to create darker scars due to melanin.
It will be an ugly scar if your body tends to create
keloid scarification which is when skin cell overreact growing and regeneration of skin and so the result is a bump scar. This is on genetics so if you have it there's no way to avoid it, radiation is used to reduce keloid formation but doesn't eliminates it at all.
Medical facts: if you get circumcised as an adult scar will be more noticeable due to age, but shape will be more defined and the amount of skin removed will be more under control since genitals have pass development stage. Men who were circumcised after birth had years or advantage in the cell regeneration and since major stages of growing are childhood and adolescence there's plenty time for cell regeneration, so usually scar is less noticeable, and not so perfecty shaped, but due to teenage years and their effects on genital development it's one of the major backdraws concerning to functionality (type of cut, penis dimensions, amount of skin removed and skin movility).
If the skin tone of your glans is very different from the shaft it will remark the union no matter if the scar is unnoticeable.
Unfortunatelly the resulting scar of a circumcision (or any other surgery) can't be predicted efficiently.
I suggest you to visit your doctor, i think circumcision it's a radical step as a solution to your problem, and i'm afraid is not really the best one. Irritation of glans can be produced to a particular soap, which is mostly the real cause. So if this is YOUR case, circumcision will get it worst instead of ease the problem, since your glans will not be protected anymore. Believe me, having a doctor as a father (he was director of a major clinic, now retired) i always had access to a lot of medical books.
I think practice circumcision as a regular procedure after birth it's stupid.
I think go against circumcision is stupid too, since there are cases where is needed.
Circumcision must be option and a personal choice (if it's not need for it in medical terms).
I choosed to get circumsiced just about 2 years ago, so feel free to ask if you still have questions.