Now I just have to wrap my head around the FLR(M) application! :-)
Luckily, the FLR(M) is much more straightforward - you just send pretty much all the same documents as you did for the fiance visa, but just updated with new dates (i.e. new payslips/bank statements, new employer/landlord letters etc.).
As you will be married by then, instead of all the evidence of communication while apart, you just include your marriage certificate and a photo.
The application also requests up to 2 years worth of evidence of living together in the UK (6 documents in each name sent to the same address), depending on how long you have been able to live together - as you have already lived together for a good chunk of the last 2 years, you'll probably have most of this already, so you just need to add in anything you receive between now and when you apply.