What weight do you need to be for weigh in? At 90kgs, 4 to 6 weeks out (and 5'9) I am assuming that you also have to cut weight. You could try LGD as that can be used for cutting and will help with strength and stamina. I would run LGD for 8 weeks, bridge for the first 4 weeks and HC Generate for the next 4 weeks as well as adding Forma of the last 4 weeks which will help you get leaner. You will need to do a full PCT upon completion though. In terms of being tested, I can't see you having any issues with HCGenerate and I don't believe that they can test for LDG yet. You may need to stop the Forma a day or so before you get tested, but not 100% sure on that so you will need to check that out.
Let me know how you go.