Go with a 200 amp "rated" panel with at least 40 breaker openings. However, the size of your incoming service will dictate the size of main breaker you will be putting in. Your main breaker will be sized according to your service entrance conductors and the incoming power company conductors. They may only be designed right now for 60 or 100 amp and it would be more expense to upgrade those depending upon your distance from the power transformer, etc. You may have to pay for the upgrade of the entire length of the cable including the power company's part.
However, even if you are advised that you only need less than 200 amp conductors coming in for your size house, (such as 100a or 125a) still get the 200 amp rated panel with a smaller breaker for the future. If you can afford the 200 amp conductors then go for it.