For each MT4 trading account, the trading server is assigned depending on the account number. The server number doesn’t depend on the account type you are going to trade with.
For MT5, the accounts are automatically created on a single "FBS-Real server".
It’s technically impossible to change the server number or create an account for a specific server, as they are distributed in a particular way to reduce the load and increase the speed of order execution.
The server number and IP of the server are indicated both in the account settings in the Personal Area and in the letter sent to your e-mail when creating a new account.