If you have never run either Ostar or RAD before, I would recommend running them seperately. SARMs can affect people to varying degrees in regards to blood pressure and lipids, and can do so relatively quickly. The more 'new' compounds you have in your stack, the more difficult it will be determining which one is causing issues should they arise.
There are many options available to you here, in terms of dosing, stacking, etc. Each of them has good arguments for and against, so there is no real "absolutely must do it this way!!" template.
Further, as for diet, you could get quite involved here and manipulate your kcal intake (especially CHO) over the course of your cycle to take advantage of each of the compounds and to try and 'maximise' recomp effects. Again, this type of in-depth manipulation is not necessary, but if youre motivated to do so it could certainly help.
Basically, and generally speaking, I lean towards the school of thinking where you try and get as much from your stack as possible, in terms of trying to stretch your supply out. That is, instead of stacking 6 products for 8 weeks, spreading them out a bit more and getting a 20+ week run (Im including PCT here, too).
