Lol if it were me, I would get both products and run them together. I've run Epi-GH and my results were awesome. Full discretion I was utilizing other things concurrently but I definitely noticed when I added the Epi-GH in and noticed different results and effects because of it. I haven't run Endurashred, but I'm coming to the end of my run of Primeval's Super Cardarine, and I've been running Olympus Labs' Ostar1ne along with it the last 3 weeks. Cardarine has definitely helped me stay lean/lean out more, work out longer and harder, and I've been able to eat all day long without gaining fat as I end my cycle. Ostar1ne has noticeable kept my strength up.
Between the two, my personal choice would be Epi-GH. I would buy 2 bottles of it and run it for 2 months at 2 caps per day. You could even get some of Primeval's Epiandro Max so you can run a higher dosage of Epiandrosterone without having to take a crazy amount of MK-677 too. I leaned up like crazy on Epi-GH while KILLING pretty much all of my personal records in the gym. I can only imagine what would have happened if I had been running a real dose of epiandro (2 caps gives you 150mg, and most recommendations are 300-400mg for the average user).