Yes, you should be checking under "Version", not "about". About shows the version of the Windows OS, but Version shows the Samsung specific information.
I would download and run the update tool from Samsung because it's best to be on the latest version. If I haven't mentioned already, if you get tired of the custom ROMs and want to revert back to the preinstalled software (i.e. with all of the Samsung addons), you can always run this tool again to do so.
http://www.samsung.com/us/i910/softwareupdate
Extract the driver RAR file into a folder somewhere on your PC and run the setup.exe file. This allows your PC to interface with the phone when you connect it. I would restart after running just to ensure they got installed properly.
UMDL also runs from your PC; this is where you select the ROM to be flashed.
I posted the ROM file
here on my own web server - I flashed this exact file to my phone and it worked fine. I know those two part RARs can be a bit temperamental.
I'll give some of my flashing steps too, for good measure: power off the phone, disable ActiveSync on the PC (right click icon near the clock, connection settings, uncheck allow usb connections), open UMDL, click PDA, select bin file you downloaded, click Detect, plug in phone to PC and power it on. The phone's screen will show the same Samsung Omnia logo but will show some messages on the screen. Flashing process will take 2-3 minutes at most.