sync fingerprints between different fingerprint module

We want to make a rollcall device for a company, but we have some serious problems, here are most importants:

What is the best fingerprint module for industrial projects (like this)? How we can connect fingerprint modules to each other that the fingerprints can be accessible in all devices? Is there any way to store fingerprints on external storage instead of module's memory?

Description for question 2: for example, an employee has stored his/her fingerprints on device A but he/she be able to register his/her rollcall on device B, C or etc. In other words, all devices be synced to each other.

What is the best fingerprint module for industrial projects (like this)?

Don't know each manufacturer would claim theirs is best.

How we can connect fingerprint modules to each other that the fingerprints can be accessible in all devices?

Basically this is just a matter of downloading the data template into your central database. Each fingerprint is about 4K. However that requires the template matching software to run on your central controlling system. You could download the fingerprint template to the individual readers for a small number of readers. You need to scope your system before you begin to design stuff.

Is there any way to store fingerprints on external storage instead of module's memory?

Yes.

However, if you are asking these sorts of questions then this project is probably beyond you. I used to work in access control and what you want to do is not trivial. It takes hardware and software skills way beyond what we could possibly help you with here.