are you both going to live in the property?
what about your wife?
are you all wanting equal shares, or is it 1/2 yours (and your wife) and 1/2 MIL
What do you want to have happen to the property if one of you dies, if you get in a huge arguement and want to sever ties, if one of you decides they want to sell their interest.
Are there any advantages either in taxes or financing to hold title in a certain way?
Those are just a couple of things I could think of, I am sure others will think of more