Illustrator cs6 64 bit version (if you are running 64 os). CS6 has been the first version since CS3 that I have found worth the upgrade. The new imagetrace feature is great. It may not be so great if you are not running 64 bit os and solid state hard drive. I also have flexi 10 but still prefer illy. I would suggest learning in a true graphics program and not a sign graphics program. They have their place but illy is so much more powerful and you can do all the same things-it might just be a little more complicated at first. You can take online, 6 week courses and be very comfortable manipulating the software in no time.