JR pass

Hi,
We intend to travel to Tokyo, Nagoya, Kyoto, Hiroshima, Beppu, and then by car around the island back to Beppu, then Osaka back to Tokyo, and we wanted to buy 2 JR passes for 21 days.
We are in New Zealand so wondered if we purchased them in August for the 1st October departure whether we would be able to use them later in the month of October.

I am worried that they will not arrive in time if I order them any later and I want to pay the old price, not the increased one obviously.

Also, any help regarding which pass to cover trains and local cities would be appreciated.

Many thanks
Kath