Installing drivers before installing Mac app - rejected by apple review team
Without recoding the app the meet Apple's guidelines, you will have to rely on selling your software outside the MAS. Plain and simple I'm afraid.

There is no way around Apple's guidelines. They are written for a reason; to protect users from having apps install malicious components or components that may damage their systems, to promoting an exceptional users experience. Having your app pull down drivers is not an ideal solution and I would not install such an app. Either make do with the existing driver set, or find a workaround that won't break your program.

You are the developer. You know the codebase and the requirements as an Mac Developer. There is no loophole. Either you are asking us to provide you with a way to circumvent Apple policy or tell you how to code your app. In both cases, it falls outside the scope of what we do around here.