Have you checked in to the winemaking standards for your area? Not sure what, if any, rules/requirements are for your market but I would think you would want to make sure you do not need to get your recipe approved or any other issue which could create a problem or delay.
I also agree that if you are looking for a mead that would ideally be ready to sell in less than 12 months you need to keep it simple--and sweet. I would think you would want to master a base mead. A classic formula, traditional honey and water, plus nutrients. If you want a pyment you could add your grapes (or other fruit/juice) when you have hit the 2/3 sugar break, as this could help maintain the fruit flavor that many desire.
There are many recipes and notes available at-- http://www.brewery.org/brewery/library/beeslees.html
You can create a nice mead in under one year. I have successfully made red raspberry mead for two seasons now, and each time the melomel has been ready to drink within seven months from the date I pitched the yeast. I did not use bentonite or any fining agents, and I did not filter. It can be done. Does the melomel improve with age? Of course.