I wouldn't use "whether" this way. You see, it is common used in negatives and sometimes it is confusing because it seems to be like "if". The main difference, I guess is whether is not about conditionals/conditions, but possibilities, different ways things can be....
To say seja there are many options, thinking about the idea of "seja A ou seja B" or "seja assim ou seja assado."LOL
Use simply "or", "that is", "so that" and even "either"