Sorry guys.. I am noob about hardisk.

Just need your advice and expertise guys, I want to buy hardisk which might be 3TB consist of 1 TB each.

3 hardisks. I don't want to but external as it might be expensive, thus i am planning to buy internal hardisk. What is the name of the casing for internal hardisk that is portable for me to bring any where?

Any suggestion for hardisk to buy and the casing. how much will it cost?

i got it ssjben..thanks..i think this will be cheaper than external hardisk aight..

which shop in lowyatt do you recommend to get this? and alos can you advice me on which hardisk to get? tq