Best Process For Data Load

Hello
I am looking for some advise.
I have a process to import flat text files. We are importing data from five vendors. These files are seperated by vendor with each vendor having their own directory. The general file layouts are different for each vendor.
Each vendor may have up to five different types of files to be imported that are their one directory (sales, inventory, transactions etc). Sales file for Vendor 1 is different layout than sales file for Vendor 2.
Each vendor may have multiple instances of each type (store 1 inventory, store 2 inventory, store 1 sales, store 2 sales etc.) There could be up to five hundred files (of the five different types) in a given vendors directory.
I am using an import package. This package has five (.dtsx files) different data flows. Each of these data flows has connection managers that connect to the specific types of files (sales, inventory, transactions etc) for that vendor.

My current play is to have the data flow(.dtsx file) parse the store name (from the file name) for each of the file types. It would load/process each of the available file formats (sales, inventory, transactions etc) for that store in that vendor folder. We want the process to load all data files from a given store. It would then move on to the next available store (same vendor). I would like to set the process to run multithreaded so that I am loading as many of the stores for that vendor as possible (there could be over a hundred stores for each vendor) at the same time.
How do I get each dataflow to run multiple instances (Instance1 for vendor(x).dtsx, instance2 for vendor(x).dtsx etc) for maximum Vendor(x) input.
What is the best way/process/design to track each store name so that each process (instance1, instance2 etc) is loading a distinct store. The files will be moved to a history folder as they are processed. Should I have a different process that gets each store name initially and then saves that information to a SQL table. The dataflow would load the next available store name from the SQL table query and let SQL lock that store?

Any suggestions are welcome and appreciated!