299 is $18,000 399 Evo is $30,000.
The Evo plus from what I can see is a 3 axis machine instead of the 299 2 axis, also it can have an auto feeder for cutting multiple keys at once.
Don't forget that these way about 20kg so on top of what ever savings you might get from buying one from the states add on the postage, then on top of that the machine will be 110v so you will need to step the voltage down on the machine. If something breaks on it and you need to get it serviced I doubt LSC would want to touch it. Then unless you know all the cards for the keys that you want to cut you will need something like Instacode to cut the keys, so add $2,500 on top of the cost of the machine.
If you do decide for the unicode you only need the 299 as you wont be needing any of the functions on the 399.
Most importantly, what is your budget for this and what do you expect to get out of the machine?