General ACCATaking on a Skills paper with a Professional paper.

Hi, I have completed 8 papers so far (waiting for the results of the last one hope I pass) and I have done all the exams one at a time. I currently have the AA paper left in Skills and would like to do SBR along with it but I'm not sure if I should, because whenever I tried to do 2 exams before I start studying close to the date of the exam (typically 1 & 1/2 months before) and only end up doing one paper. But I thought that if I start studying now I might be able to take 2 papers, then again this isn't like taking 2 skill level exams since the SBR exam looks much more challenging then anything I have ever faced before. If possible can anyone guild me on what I should do taking all I've said into consideration. Thank you.