Securing access to WordPress admin pages?

Hi - hoping someone might be able to help.

We were looking for a way of securing our WordPress login details for the admin pages so that we don't send the password in the clear across the internet.

The obvious way to do this would be to use SSL so that the password is encrypted, but from a recent chat with support, it seems you can only set up SSL with a CA authenticated certificate. We're not bothered about authenticating the server, we just want to encrypt the password when it is sent, so a self-certified certificate should do the job, but it appears we aren't allowed to use one of these for SSL.

What does anyone else do to secure their WordPress admin pages? Is it a case of pay for a CA certificate or send in clear? Just a bit paranoid about packet sniffing given the website was hacked recently.

Thanks for any help anyone can offer!