Amentoflavone XT and PEAK02 are both great products.
For me personally, PEAK02 is better for cardiovascular endurance - I feel like I can do cardio much longer and easier, whether its on the treadmill or in day to day life like hiking, soccer, or rafting.
Amentoflavone XT I think would slightly have the edge for muscular endurance. I don't think you would see yourself necessarily lifting more weight in your first couple sets, but would see your strength levels higher later on in workouts via improved endurance. For example, if you do 12 sets for chest - I think Amentoflavone XT isn't necessarily going to help you do more weight on sets 1 to 4, but you would see the difference in sets 6 to 12 in that they would come a lot easier and strength would carry over later on into the workouts. I hope that makes sense. (Epi-Plex works great for this for me as well).
For overall strength gains, if the goal is just strength gains in general, I think Anabolic XT and Phosphatidic Acid XT are great options.