Are there any other hardware stores, or stores like Wal-mart who sell everything, in your area?
Oh, so the T8 are the fatter bulbs, the T12's the skinnier ones? I just can't recall.. No that can't be right. I thought you could use the skinnier (has to be T8) bulbs in the T12 fixture, but not the T12 in the T8 fixture. Sorry that I wasn't any help.
a t8 will work in a t12 fixture bot not the other way around, the t8 is skinnier than the t12. they both have the same ends. I did some looking myself recently. menards (in wi) had them. home depot did not. if you have a lowes I would try there. we don't have one close enough to warrant a drive for me.
but to simply answer your question of will it fit, yes, if you have it in either t8 or t12.