Can you share some pics? No easy way round this, FUT scarring can be a issue, absolutely no guarantee it will end up pencil like thin, and it can take a certain length for it to be covered. FUE will scar, but it’s thousands of small dots. Again you won’t be able to go too short, but some guys do fades no problem.
It’s a lot of grafts either way, if you decide FUT then you would want a large session from either H&W or Hattingen, if you go FUE then you definitely don’t want a huge amount of grafts done in one day, it would need to be multiple days. You wouldn’t want anybody doing it quickly, it’s going to be a long day/multiple days..