I use ZAGG InvisiShield on all my LCD products, especially my camera bodies. ZAGG product includes smaller protectors for top and bottom windows, as well as, the main LCD.All are good, personal preference is ZAGG.
Definitely get the Giottos! It's made of Schott German Glass and its' very nice! I use these on all of my cameras, as they come in different sizes. The clarity is great and they don't bubble up.The MKIV uses the 3 inch model below:http://www.bhphotovideo.com/c/product/483871-REG/Giottos_SP8300_SP8300_AEGIS_Professional_Glass.html