Audiometry is enough to purchase HAs online?

[Lulu]

I'm from Peru and I will to import HAs from US.
I will to import Siemens Pure Binax.

Audiometry is enough to purchase HAs online?
is not mandatory other tests like Tympanometry, Logoaudiometry, etc. ???


PS:
Which is the HAs with better sound technology (noisy environments, etc.)
Siemens?
if So, Ace Binax? Pure Binax? Carat Binax? Carat A Binax?

Thanks so much guys!!!