The 203(K) programs take at least 60 days to close.   First, only work with a banker who has closed these many times before.  You need a local HUD inspector to give you a list of "must do" fixes, then you need a contractor (or multiple contractors) to bid on this job, and any other items you might want done.   Also, terms are changing this month, and all the rates are going up.  

It is may more complicated than conventional financing or just paying out of pocket for the work.