If you have a question/suggestion for Staff, make a thread in the Threads Involving the Staff Forum. Avs are set to this size for uniformity and aesthetic reasons. If you wish to frequent a forum just for the size of it's avs and sigs, then you can find plenty of them out there that are not EoFF. EoFF would rather have/see quality posting rather than more flash.
BTW, your sig is also over the 250 pixel height limt.
