do I need a visa or just the residence card?

Hi,

I am currently on a work visa which will expire in 2 years. I don't intend to stay at my current job so I am not going to extend it. The problem is that my husband and I are applying for a mortgage and they might ask me to show that I can stay here long term. My husband is a EE national. I called up home office today and they told me to get the residence card using the EEA2 form. I was wondering if that can be used instead of the visa? I am from Hong Kong so I can enter the UK without a visa, but I don't have the right to stay over 6 months a year. I am confused. I thought I would have to get the spousal visa instead of this residence card?

thanks!