Marco,
you will need to go down to about 0.5Vdc for small zinc plated items. Range is about 0.5 to 1.5Vdc for Zinc. For copy Chrome the voltage range is around 2.0Vdc to 3.0Vdc.
If you are not doing real chrome then I would suggest a 0 to 5Vdc power supply.
As far a current is concerned, try to work out what you think the biggest part would be that you would plate in square inches of total surface area. multiply this by 0.1Vdc and this will give you roughly the maximum current you will ever require for plating.
I picked up a great 0.8Vdc to 15Vdc 60A power supply from a HAM radio (Amature radio) supplier for a very good price.
See the example in the link below.
Andrews Communications - Electronics
Note: Its the SP-9600 it says it is a 60A 1Vdc to 30Vdc. They actually go down to 0.8Vdc.
Cheers
Mark