Inventory Maintenance

I own a local convenience store and need a better way of tracking inventory that what is currently being offered on the Clover POS platform. The Square POS which I use to use is a good start but I want to expand on how theirs works with added features essentially creating a new robust way of tracking all inventory in a retail setting. I would like a way to track profit margins by adding in the cost of an item along with the sell price of that particular item on the details window. I would also like to be able to add a custom remark on the Manage Stock window under Stock Action.