Siebel

Hello,
We will have a new pre-production hardware available for Siebel 8.x upgrade several months in advance. This hardware will be same as prodcution with respect to size. We are planning to use "Data guard" for replication from Siebel 77 DB (2.5TB) to the new pre-prod Siebel 8 DB server. My requirement is to have minimum downtime!

I am thinking of following upgrade steps before the deployment weekend.
1. Take cold backup of Siebel 77 PROD DB
2. Copy 77 PROD database to the new Pre-prod Siebel 8 DB
3. Install and Siebel Gateway server, Siebel server, Siebel database server utilities and Siebel web server extensions
4. Install database schema and seed data
5. Import the new Siebel 8 repository
6. Test the application
7. Shutdown Siebel application and get ready for production deployment

Production deployment weekend steps:
1. Shutdown Siebel 77 application and DB
2. Start Data replication from Siebel 77 DB into the new Siebel 8 DB
3. After replication complete, Start Siebel 8 application.

Can any one confirm that the above production deployment weekend steps would work, meaning does the "Data guard" replication keep my Siebel 8 upgrade DB intact and not wipe it off? I am trying to avoid installing/configuring/upgrading the application during the deployment weekend.

I am lost and confused on how the production upgrade is going to work. I read several online posts, upgrade guides, and did not come across good information/help for production upgrade, all of the support articles are for upgrading development environments!

Please note that "Golden Gate" is not an option, do not have budget for it!

I would appreciate any help.

Thanks,
PM