I also think that booking companion ticket will be easier, but it seems not in your case. My suggestions:
* Buy upgradable tickets (YBHK) and upgrade both of you. It will be much less expensive but require a lot more miles.
* I assume your wife does not have a MPC Gold status. Buy your wife a business class ticket and get yourself a companion ticket. It should be much easier getting a companion redemption for yourself with your MPC Gold status.

Of course, it is wise checking redemption availability first before ticketing the non-redemption one.