Hmm...from what i've been researching here it seems that if I get a hair transplant while i'm kind of young (i'm 27) and still losing hair, i'll still lose hair in DHT prone areas and it'll be unbalanced. I take it minimal surgeries is better for minimal scarring etc. so in that case it would be best until I lose as much hair before I absolutely can't stand it and THEN get my transplant.
At this point, I can either hop on finasteride to slow it down as much as possible or just wait until I lose a lot of it to get the transplant.
First of all, get the f*** on finasteride right now. Seriously start making calls to derms/hair transplant surgeons in your area today. If you get sustained sides (aka sides that persist after the first few weeks and you can minimize the initial ones by stating on a micro dose every few days and working your way up to 0.5mg every other day) then just stop taking it and you have like a 99.something% chance of recovering and going back to the way you were. A very small % of the small % of guys who get sides have them persist long after stopping, if you're gunna get a hair transplant then you're already taking pretty significant risk as it is, I've never understood the hesitancy to tack on the low finasteride risks along with it, but anyway...
The thing is, you don't know how far your loss will go. That's why finasteride is so crucial on younger hair transplant patients, it halts the loss for a long f*****g time (lots of guys have been on it 15-20 years and maintained their hair). This is even more relevant for us today since there's a lot of promise in the regenerative medicine field, if you can halt native loss for 15+ years there is almost assuredly going to be an alternative available to continue halting it, maybe even reverse it. The phrase "an ounce of prevention is worth a pound of cure" has never been more relevant than with hair loss.
Once you have it halted on finasteride (I suggest taking it for around 2 years before getting a hair transplant and confirming it has halted loss and you have no sides) then you can better plan your hair transplant. Lots of ethical docs strongly advise against doing the crown on younger guys because of how unnatural it looks when the circle of loss widens and there's a patch of transplanted hair in the center plus then you're chasing the loss and the crown is a black hole for grafts so you'll kill your donor supply, which is another reason for you to get on finasteride NOW. Trust me you don't want a thin/exposed crown when you're young. Also, it doesn't take much at all to go from a Norwood 2.5 to a full blown Norwood 3 where you lose all styling options and become a full blown sub human baldcel with no frame to your face. Take finasteride before that happens, trust me.
Finally, as far as a hair transplant, no you don't have to wait until you're super f*****g bald unless you're in the midst of a massive aggressive shed and are looking like you're heading to Norwood 6-7. The results are more of a home run the more native hair you have to support it.
The decision between FUE or FUT in my opinion (assuming you're going to a top Doctor for both, FUE takes more skill to pull off a great result so choose your Doctor carefully) comes down to donor graft supply and your best guess as to future loss based on your age, amount of loss and the pattern of it plus your family history of loss/pattern. Konior confirmed to me that the best way to max out donor is to FUT first until you can't anymore then switch to FUE to fill in as needed from there. So if you think you're heading for a Norwood 5 eventually (you have to plan as if finasteride will abandon you and no other treatments will surface), it's better to FUT first since you'll need 8-10k grafts to get a decent looking result over that area of scalp and FUE doesn't usually get more then 6k grafts out of a donor. If there's no history of that in your family and your crown/midscalp aren't miniaturizing then FUE is a good option (if the person doesn't want the thin strip scar, they can still do FUT if they want obviously). Or if you absolutely cannot abide by the strip scar then you can do FUE and just take your chances of running out of donor, and it would be smart to go conservative on the hairline rebuild.