iMac with Leopard or Tiger?

I will be buying a new iMac soon, but I'm not sure if I should wait for Leopard. I currently run Tiger on a Macbook. Will the restore discs with the iMac load Leopard on my Macbook (if I wait for Leopard's release)? Will the Migration Assistant work between Tiger and Leopard to load the Macbook data to the iMac? I would like to have the same OS on each machine. If I buy the iMac now and buy Leopard later, can I load it on both systems or do I need to buy a multiple user package to do that. Thanks for any replies...

I would guess that you'd need a multiple user package yes. And as far as I know, data transfer between macs should be fine. Was it ok between OSX 10.3 and 10.4? I think it was. It's not a whole new OS, just an upgrade, so all should be pretty smooth

I will be buying a new iMac soon, but I'm not sure if I should wait for Leopard.
There is no reason to wait.
I currently run Tiger on a Macbook. Will the restore discs with the iMac load Leopard on my Macbook (if I wait for Leopard's release)?
No.
Will the Migration Assistant work between Tiger and Leopard to load the Macbook data to the iMac?
Yes.
I would like to have the same OS on each machine. If I buy the iMac now and buy Leopard later, can I load it on both systems
No, not according to the EULA.
or do I need to buy a multiple user package to do that.
Yes, that is what you will need to do.

Thanks again...good info.

Apple do a 5 user "household" license for not a lot more than a single user license, so there's really no reason not to go for that. I suppose it's Apple's way of getting people to go the legal route; if it's only a little extra to install it on 5 computers legally then why not?

Indeed,

So when I buy my new iMac before October, I could share Leopard license with my brother in law

In my eyes that's household

(the word says law! don't suggest its illegal then!)