Are you comfortable using the terminal and UNIX commands?
Then it's a piece of cake. When you get the new drive copy over your home directory to the new drive wherever you want to put it. Then rename your home directory on the old drive to something like home_backup, then create a soft link with the same name as your original home directory and make it point to the directory on the new drive.
In fact, you can do this in Finder w/o ever opening up a terminal.
Or you could just edit the /etc/passwd file to reflect your new home directories location. But in case anything else in the system explicitly references your original home directory path, you'll need to do it the first way.