Yes, you should upgrade to Windows 7 Pro, here's why.

This is what I did, so I have some experience with this. First, upgrade to Window 7 Pro. Because in Windows 7 from Pro up, you can down load, and install, from Microsoft, a virtual copy of Windows XP that runs inside your Windows 7. This way, if you have any legacy programs that won't run in Windows 7, you can install them in you virtual Windows XP, and still use them.

Next, right now, buy from Microsoft the Windows 8 Pro Upgrade. The sale ends on it February 1st, and the price goes up to over $100.00. So, get it now, while it's cheep. You can install it later, really, any time.

OK, now down load from Oracle, there free virtual machine "VirtualBox-4.2.6-82870-Win.exe". Down load the user manuals too. They're in PDF format, so any one can study them.

From your Windows 7 environment install, and set up a virtual machine using VirtualBox. Then install Windows 8 in that virtual machine. It's an upgrade, so you'll have to install something in the virtual machine first. Perhaps you still have your old Windows XP installation media, or you could use the Windows 7 media. It doesn't matter, because during the installation of Windows 8, it gives you the option of completely removing the old operating system.

So, what you end up with is one computer that is legally running Windows XP, Windows 7 Pro, and Windows 8 Pro. It's the best of all worlds, until you decide what OS you want to run as your main OS.

Good luck, and read the manuals.