Iphone 5s, SE, 6, 6s or 6Plus?

hey guys,

i am looking at buying an iphone.

my requirements are as follows:

facetime,
64gb,
long term use,
economical

what are your suggestions?

thanks in adv.

cheers,
t

Read more: Iphone 5s, SE, 6, 6s or 6Plus?