Advice on raising parrots/parakeets in Vietnam

So I found these guys in a shop on my street.

https://fbcdn-sphotos-c-a.akamaihd.net/hphotos-ak-prn1/1525228_10151863633151094_1118399278_n.jpg

I want to buy them come payday and give them a proper home in my new apartment.

My question is what should I know in regards to raising them in Vietnam? How much does a good (properly sized) cage run for? Can I give them the regular tap water or should I invest in some special water for them?

P.S. While this new format looks pretty good on my phone, it looks just atrocious on PC....

Since you need special water for yourself you may as well give it to them too. 

You will need an avian vet.  The only one I know of is Dr. Nghia, http://www.saigonpet.com.

Get an exam.  We bought a macaw here and he died a few weeks later.

Oh god. That happening to such a beautiful bird like a macaw would traumatize me. To be honest, I'm wanting to get those birds partially just to help me cope with some stress of daily living so yes, I don't want to have these birdies just belly-up on me later. I take that the only way to get that exam is to actually buy the birds, yes?

Not as traumatic as the Hyacinth, Scarlet, and Harlequin I had to leave in the USA