As mentioned above, a savings account is what you should use if it's short term (< 5 yrs) for the majority of the balance. You can put some in the market if you like, but it's sort of a gamble. Sorry, I lied. It is a gamble. No one can predict what the market will do in 2 years.
On another topic, I would recommend you try to sell your current home ASAP. If it does indeed take some time, you want to get started while the housing market is as good as it's been in a long time. Take a loss if you have to, but at least you know where you stand. Rent it out if it is a reasonable investment property, but otherwise take the hit and move on... unless you feel strongly it's going to appreciate.
If it does sell, you can celebrate! And then, you have a few options.
- rent from new buyer for a few months, if they will go for it
- put the majority of your stuff in storage, and find a short term rental to help with the transition... depending on how long it will be before you move
Just a few other ideas I didn't see above...
good luck