You got to break it down into a ratio of movie vs TV/ video game watching. If you think you will be watching movies over 50% of the time than a 2.35:1 screen may be a good choice. If not get a 16:9 screen and masking of some type. Theater looks great! What speakers, electronics and pj do you plan to use?
JBL Pro Cinema-JTR subs-Sony projection-Elite AT screen-Denon/Oppo electronics-Acoustimac panels