Hi Beccarose,
Just from your last response, there's the potential for a lot of misinformation on the web, as you've found. The trick is to research a little deeper and to compare to other sources of knowledge as well. There's always information that is 'known' about but isn't 'posted' about.
In this case, I've done as mentioned below, and taken 6 months rent up front. I'm a private landlord as well and prefer long term renters that are respectful and trustworthy. If you can, do try and search out a private landlord as you'll find more flexibility. However, do keep your wits about you as of course there are idiot landlords out there as well!
Cheers, DtM! West London & Slough UK!