Hi Japan,

Im in Tokyo myself and I would say go for 60% at first considering.
65% and 70% is a lot of hair.

Ghost bond is good also supertape, if you sweat a lot and lift heavy weight like I do I would go with blue lace tape for sides and back taping.

Just go real easy when pulling it off the system.
during summer months ghost bond and blue lace or walkers tapes and glues hold up well.
For humid japanese summers I found that other tapes and glues had a hard time sticking and tended to lift .

but thats because summers are so wet and muggy in Japan.

hope this helps and yes SFS is the most undetectabe although you have to handle it it with care as its more fragile also.