yes you would just need an invite letter from your GF. if she owns the condo then you'll need the house book as well, that should prove she owns it. if she is renting, you'll need a copy of her lease agreement and the house book.
But if in doubt call your embassy and ask them what is required.
As for a regular tourist visa (
@Stu***
) You don't need to prove any accommodations. on my forms when i arrived last month i just put down an address. upon check out of ASQ they asked if that was the address where i'm staying and i said yes. no one checked anything, and i didn't have to provide any proof.