Rose Gold watch case

Rose Gold is not an option. I would suggest that you take your band to an Apple Store, if possible and see what it looks like with the available options.

Of course, the new watch will come with a band. You can preview options here:

Create Your Apple Watch Series 9 Style - Apple

The Watch 8 series is not new. In fact, it's now almost a year old. It is no longer available for sale from Apple.

You can see Apple's current offerings here:

Watch - Apple