Wish I had an answer for you, but I have been thinking about starting a very similar thread.

DS sleeps with me so it's not so bad, but DH is taking his cot out of our room today because he just won't sleep in it.
Same as your DD he hit's the side because he's such an acrobat and wakes up.
It's so bad that we have a trundle bed (ie low to the gorund) and I'm seriously contemplating just putting a bedrail on that and letting him sleep there. He sleeps so well on a 'big' bed.