8 hours should be ok as long as you leave them something to do and a large enough cage. Make sure you have enough room for a large cage, a large playstand and a large bird. I would definitely make sure you are ok with the sound level and the large beaks.
Most birds love to come along on vacation, just take precautions so you know they are safe. I know several people who take their birds rving.
What size cage are you looking at?
I like this one because of the size (lots of room for perches and toys):
HQ Giant Double Bird Cages - Presented by BirdsComfort.com
and this one because I'm partial to the victorian top:
HQ Victorian Macaw Bird Cage - Presented by BirdsComfort.com
There are lots of great things to leave your parrot to do during the day,
Here is a great free activity book:
The Picky Parrot
Some different foraging toys:
The Picky Parrot
Make sure you look into dry foods, such as different seed, pellet and other mixes:
Avian Naturals* nutritious healthy natural parrot food parrot supply treats gifts parts
Phoenix Foraging Rolls
Playstands:
This is a great foodstand, trust me its HUGE:
Bird Feeder Stand - Presented by BirdsComfort.com
I made my own version of this (but where I live where there is a lot of bottlebrush and cajeput trees):
Bottlebrush Parrot Play Gyms, my original design, handmade parrot gyms you and your bird will love.
Make sure you ask the breeder how they socialize the baby, heres an article on how one breeder socializes their babies:
Cedar Mountain Aviary
Hope that helps!