OS X makes it easy and has supported having home account on any volume anywhere for 10 yrs, since 10.2.2 from inside Accounts control panel with little to no work.
RESEARCH the reliability of the OWC PCIe SSD first. It is subject to corruption. It does not really work pre-2009 but you are safe in that regard.
There are guides how to move and setup an home account and SSDs. On the forum, google,
Even the terminal which will, is rather easy and allow and best when handling more than one (like 20 users) but no need for you.
If you can't find it from Google someone will hand it on a spoon...
Spoon? This one?
Here are two similar recipes and discussions on the subject of moving the Home folder -- no Terminal required
This also raises the question if you move your Home Directory what is the story on Home Directory programs like mail or your Documents.
Mac OS X is inherently a Multi-User system.
Applications, such as the Mail Application, are stored in the Applications folder at top-level. By default, any User who logs in uses that Application with their own individual email data stored in their own Account in the /Users directory. There is no need to have multiple copies of the Application.
[In fact if you try to make a copy of Mail Application somewhere other than in Applications, you will probably end up with your Mail program disabled because it is a huge Security Risk.]
Your Documents are by default stored at /Users/<your_name>/Documents. When you use the recipes or Linc Davis' detailed procedure, you are re-assigning the location of <your_name> Directory. All your document references move with that re-assignment (you still have to manually duplicate the <your_name> Directory), and all the Applications stay in the same place in the /Applications folder at top-level.
I prefer a setup where the original Admin account is used ONLY for Administration, and is left alone on the Boot Drive. User Accounts (including my own) have no Admin rights, and are all moved off the Boot Drive.
You can get even more extreme than having User files on a separate drive. They can be on a different computer. I run my home Network as if it were a School setup with computer clusters (because I do some school consulting). User Accounts are all on a separate computer running Mac OS X Server. Any User can log on at any computer and their files are instantly available (from the Server).
Many thanks to all of you for pointing me in the direction of the solutions and the best ways to use both drives. Before I do anything I will do a total backup which is very much in my usual operation - a backup freak! It looks as though in this process, making a disc image of components will work better than just a conventional backup. I may also use my 2006 MacPro as a test bed just to see how things go before I try the installation on my "working" MacPro. What started this whole thing was my installing an SSD in my aging Mac Book Pro - talk about giving new life to that laptop! Wish me luck!