Not only does the credit bureau max out their password length, you have a small list of available non-alphanumeric characters you can use, and no spaces. Also you cannot used a plused email address, and it had an issue with my self hosted email alias, forcing me to use my gmail address.
Both Experian and transunion had no password length limitations, nor did they require my username be my email address.
Update: I have been unable to log into my account for the last 3 days now. Every time I try I get a page saying to call customer service. After a total of 2 hours on hold I finally found the issue, you cannot connect to Equifax using a VPN. In addition there is no option for 2FA (not even email or sms) and they will hang up on you if you push the issue of their security being lax. Their reasoning for lax security and no vpn usage is "well all of our other customers are okay with this".
I tend to prefer pass phrases, they are a lot easier to type and speak, if required. Mine regularly blow past 20 characters.
As for salting, that only defends against rainbow table attacks. The salt needs to be stored along with the hash. That is find for most accounts, but once you're in banking territory, that's a bad bet.
You also can't assume you have no vulnerabilities. If someone gets your database, you can't defend against brute force attacks.
Lastly, if you are doing passwords properly, you shouldn't care much about length. There are a few dos attacks to worry about, but a 512 char limit will stop those, and not limit any sane password.
Bcrypt and scrypt both have a byte limit of 72. That's still enough for a secure passphrase, though some schemes might blow past it.