First off, find one that is comfortable and fits the profile of your Face. I believe you mentioned glasses in your original post and are wearing them underneath. You may try looking into the V-Force Grill or the V-Force Profiler, both are a great mid range goggle, and the lenses are easily replacable, as well as they fit someone with a larger face profile.
That said, you may also like the Dye i4's. I picked up a set for reffing this year, and although you will need to have a small facial profile, they have worked extremely well and are comfortable for reffing/playing 8+ hours a day.
I haven't yet tried the E-Vents from Empire, but those are the another option for you.
Same with the Sly Masks. I've got a buddy who swears by them, but I haven't personally used them.
All in all, find something that fits you comfortably, and that you like the look of. Try and find a field nearby and ask people if they will let you try on a certain type of mask, and ask for their opinions as well!