Thanks for your info and links.
I'm not in rush at all although if all of this could happen faster it would be ok. My parents are fairly young (mom -late 40's, dad just turned 50) which doesn't meant that we don't take into consideration all the issues(health etc.) that you mentioned. They have enough to settle here and provide for themselves and the other thing is that they should be able to work too. Back home(Poland) things(politically, economically) are going bad, there is a lot of corruption, slow development(if you look at big picture) and too much bribing. One can do two things either wait for things to get better(my grandmother's point of view) or move on somewhere else where is better. What would you do?(this is much deeper subject that I made it here)