Oh, that was something else! Sorry, it was a while back that I was in that situation.
The hospital I was at, gave out these little comforters. Just a rag doll kind of thing. They came in pairs, so one stayed with bub and the other stayed with mum.
The idea was that mum would put one in her bra so as it would get the scent of her milk (if she could and chose to express for bub) and the other would be placed in the humidicrib with bub. Then they would swap each day.
Meant to give some comfort to both of them to feel a little closer since they can't be together all the time.
As a pp said about clothes... they wont need clothes for quite some time, plus clothes will just get in the way of all the tubes and wires and stuff.
However it is nice to get them some things. Nothing in the shops will fit a 27 weeker! I found a range of teddy bear clothes at pumpkin patch which fit my premmie girl. They had these teddy bears that had the same clothes as the kids range. The idea was that the child could have a teddy bear dressed in the exact same clothes as them.
Anyway, not sure if they still have them, just a thought.