it depends a lot on the rental agency you use. some of them are very strict, some don't need much reference.
i recomand [removed - keep for PMs, please], they will only ask for email reference from work and email reference from ex landlord which you can easily get from a friend. make sure you declare your annual salary is high enough (i suggest the monthly salary to be 3xmonthly rent) otherwise they will ask you for 6 months in advance. this is an agency that works like this but I'm sure there are many other.