If you're interested in the way scars look you could google them, you may get some seriously scary ones though since everyone loves to post the worst possible cases of everything. I believe it's called laparoscopic (?) that leaves three or four one inch incisions. I've seen it and they don't look bad at all, my dad has the same looking scars from a hernia operation so if anyone asks you can say that's what you had done if you're the type who doesn't want to tell everyone everything because some people are nosey. (Though of course that would only be in the case where your stomach was showing...) The abdominal isn't all that bad, it's about five inches below the belly button. I heard it can be vertical or horizontal.
Also for surgery I've heard it all depends on what the surgeon is comfortable with. (I have not had mine yet, in the process of getting one) I myself and going to push for abdominal just because for me it's the most uncomfortable idea ever to be asleep and have someone fooling around down there. They all have their risks and benefits so if you haven't you can look more into each of the three types of surgery (I think there's only three...).
Your first step could be to find a trans friendly gyno, one who's had other trans patients if possible. You could try just any gynecologist but you risk the possibility of them being bigots or not understanding. Also as for you're age I've heard it does matter. My doctor said it's going to be really hard (Almost 20 and a half) to find a surgeon to do the operation. Even if the gyno approves it and says it's medically necessary you have to find a surgeon (trans friendly) who is willing to go through with it. I also have a serious chronic pain problem and I too know of doctors who couldn't give two ->-bleeped-<-s about it.
I have to wait six months (no thanks to my doctor not sending out the letter two months late) to get in with the trans friendly gyno. I still have no idea if she'll approve the surgery, so I have another on my list to call if she doesn't. So I guess my advice is shop around as much as you can with doctors until you can find one who will do it. It could take a fairly long time though.
If it's not causing you any physical problems there is a chance they will be more skeptical about you getting it done. Most people who get this surgery are late thirties to forties (or older) so it's hard for them to see it as a good move in someone who's 21. However the fact that you risk the possibility of getting pregnant may make them reconsider if it's necessary. It really does all depend on the doctor, so that is what is most important to find. Of course they will have to do an examination first (if they don't they may just be a whack job doctor and even though I hate the thought of having it done, I would not want a doctor who didn't see it necessary.).
After seeing a gyno who can refer you to a surgeon, it all depends on the surgeon. I've heard of some people who wait quite some time after seeing the surgeon, others who get within a month.
That's all I can really answer, you could check out youtube videos of guys who have had this procedure. There are a few guys on here who have had it done so I'm sure when they get around to answering you can find out most of what you need to know.
