How can I get these devices to work together like this?

Question

What we have now:
New iPad 2, currently blank
My iPhone 4s with my itunes id which is also used for icloud
Wifes iPhone 4s with her itunes id, also used for her icloud
(phones are not linked in any way, other than some music synced from same pc)
What I want to happen:
Shared account for app and music purchases across all 3 devices
Shared photo stream across all devices
Nothing else to be shared
I think the shared purchases should be easy enough. Just need to set up a new single id and use it for the store on all devices. But what about things we’ve purchased separately over the last few years? Is there any way to transfer these onto the new account, or are they lost?
The shared photostream im not so sure about. I think the primary icloud account would have to be the same on all three devices, but then a separate unique icloud account for imessage, facetime etc on each device. Does icloud maintain separate backups for each device? I would probably need to buy more storage with them all backed up to one account.
Any other drawbacks eg loss of data on the phones when making these changes?
Thanks for any ideas

Answer 1

Welcome to the Apple Community.
Changing your iTunes account would result in you losing access to all of your previously purchased content.
Photostream would require you each have the same iCloud account as a primary account, you could each use your existing accounts as secondary accounts to retain your email, sync your calendars etc to a computer, whilst keeping them separate from each other.
Backup would back up both phones to the same account, you may need to purchase additional space.