Questions regarding payment and the Systems themselves

[KageJason]

Hi have a few questions refering to the 3DS systems availible in the store.

1. Are the systems safe to update? If not, what should i do in the case of it getting updated?

2. Does the payment have to be In full OR is there another method? (Like a set amount per week/fortnight until the target cost has been reached, to which once it has, It then gets shipped) The reason I ask this is because I'm australian and the currency conversion puts one of the cheaper 3DSes avalible in the store at the Price of $400's