We have the 10 internal servers behind our ASA. We do not have any routers between the ASA and internal networks. Would you use the internal IP address or public IP address for your servers? The servers are web server, SQL server, active directory, mail server, and file sharing server. We do not expect more than 10 servers in our environment. I think the SQL server is tied to the IP address. So, if we decide to use the internal IP address and change to the public IP address, we need to go to the SQL server to change the configuration.
Go for private IPs and have the ASA translate the IP addresses statically.
This is the recommended solution if you need the servers to be accesible from the Internet.
You secure the communication via ACLs.