Issues with SharePoint 2010 installation

I was working on a new project requiring the installation of 2 SharePoint 2010 farms. Things were a little rough from the get-go, my installer for SQL 2012 was corrupted during file transfer, so after installation I had to roll it back and go with SQL 2008 R2 that the datacenter team already had in the data store. Eventually I got all of the prerequisites installed and continued with the configuration. Right from the start I was getting strange errors trying to run psconfig: First I got User doesn't have access to server or master database. Eventually I got that worked out and I started getting: User doesn't exist. HUH? Here's my process for eventually getting through all the issues:

• Made sure firewall was open for the required ports on database server (tcp 1433 and upd 1434)
• Added farm user login to the database server with public, setupadmin, and dbcreate roles (just to make sure I wasn't going insane, added the user as sysadmin, removed afterwards)
• Eventually turned off UAC on the SQL server

After these steps the psconfig createdb kicked off successfully and got to step 3. It then started giving me the error User doesn't exist. A note about my environment: My user account is in a different domain from what the service accounts and servers are in. I eventually had to log in as the farm account to run psconfig successfully. Evidently "couldn't find user" means that whatever SharePoint was trying to do, it was trying to do it with my account. Even though I was a local admin on all the boxes and explicitly added as sysadmin on the SQL server it couldn't find my account because I was in a different domain (in the same forest). Hope this helps someone, it frustrated me for a few days.