If I understand this correctly, you are looking for something like a sunconscious connection. Like twins are sometimes connected? Something where you can feel a hint of eachother's emotions and so forth.
While this is possible, I've only seen it last a short while and never in the long term. Not sure if it is a simple limitation, or somebody that isnt a twin is just not compatible.
I wouldn't reccomend it anyways. There are some things about your lover that should remain a mystery and should be able to keep surprising you throughout the relationship. Being bound together like that can break up a relationship far too early. It's like not being able to give those little white lies anymore to comfort them, and if you tried it they can see through you and think the worst of it.
So the couples retreat idea is probably a better recommendation. :)