First of all, we cannot guarantee a bestseller. That is dependent on the service that is providing that classification. For example, Amazon has a bestselling list but they generally do not make it available to self-publishers. So, that is something that we would need to consider as far as the publishing options. There are also other lists that are called "bestseller" lists. But, again, we cannot guarantee (at this time) but we can coach you in the area of best practices that provide you with a better chance of making a bestseller list.
I think what you are likely looking for here is coaching. You likely want some hints, tips, direction in how to get there with your novel. And, that can be a novel that you have written, that someone else has written or ghostwritten for you (assuming you have the legal rights), or it can be added to the package (i.e. premium package) that you order from us for your ghostwritten novel.
Our job is to impart our wisdom to you so that you can be equipped to be the best that you can be as the author of your novel. And, remember, YOU are the author in the case of a ghostwritten book. YOU get the credit!