I personally wouldn't buy an IMI conversion. I would buy either a Group or Vector gun.
I certainly respect the opinions of our Host Roverdave and Vegas SMG. Some of the Vector/Group guns have had problems, that is undeniable. Personally, my Vector has run flawlessly for the nearly ten years I have owned it. That is thousands of rounds including 5k of the nasty Egyptian surplus. Through it all it hasn't missed a beat.
Here succinctly is why I wouldn't buy an IMI conversion. For several years I compiled a database of the serial numbers of full auto, full size Uzis. I never shared this data online and I no longer have it. What I found was disturbing. While not in any great quantity, I found some Uzis that miraculously lost their blocking bars over the years. This gets even more confusing to a prospective purchaser when some manufacturers made both married slotted bolt conversions and full conversions. You can also find in the archives of some sites, posts by people admitting to the removal of blocking bars. At one time, many people people believed that removal of the blocking bar was perfectly legal.
Now maybe I'm being a bit of an alarmist, but I can envision circumstances where the ATF would compare the original Form 1 with the actual gun. I personally wouldn't want to possess a full conversion where Form 1 said that the method of conversion was by slotting a bolt. I just have a sense that post the "M11 to any other machinegun" fiasco and prosecution that the ATF is turning up their scrutiny.
Like I said, this is just my opinion. Don't ask me for the serial number list, it doesn't exist anymore.