I agree with everard: If you're planning on moving and you're worried about the ARM, then why not try to sell now and buy a new place now?
It seems to me that the transaction costs on a refi (whether it's cash-out or not) when you're planning to sell in a year or so anyway may not be worth it. And, as everard notes, you'll be ending up with a bigger mortgage. You don't say what your interest rate is now, or what it'll adjust to, but you should run the numbers just on your current mortgage, a refi with cash out (if you're even able to do that), or a refi when the ARM adjusts. I'm guessing the least attractive option is refinancing now, whether or not you take cash out.
Hope that helps.
The issue about selling your house, and finding a larger one if it sells, is most likely not a big issue.There are enough houses for sale .You might be able to reserve one , with a house to sell clause .
If you really want an other house now , I would advice to put it on the market now,price it right ,sell it in a few weeks and start looking for a new house now, and forget about refinancing.
Decide on your priority ,do not be greedy and do what improves your life the most .
For the financing you should contact your bank .I am a realtor.