Different contacts on multiple phones with the same google account?
To my knowledge, there are at least two ways to achieve this:


use a different Google Account
the most obvious variant. But probably not working for you, as you cannot transfer your payed apps to it
make use of contact groups
create appropriate groups using GMail's web interface, splitting your contacts in your preferred way. Then on each device, select to only show the corresponding group. (see also How do I sync only “My Contacts” from Google on Samsung Galaxy S? and the questions in its "Linked" section). Though in this case all contacts are synced to both devices, you can chose to only show the preferred group on each.