EQ would be the better addition - it will give some lean gains, vascularity, and endurance. Besides, unlike anavar, it is non-liver toxic. Also, since you are using trenbolone, it would be a great idea to add in some Cardarine into the cycle, as it has a time proven ability to greatly reduce trenbolone's side effects. Besides, it is always a good addition into a cycle, since there will be no additional side effects, but there will be a lot of additional benefits. And finally, EQ together with Cardarine GW make the ultimate endurance stack.
400 mgs of EQ is a good dosage - you don't really ever need more than 600 mgs per week. EQ works slowly, but that does not mean that it does not even at lower dosages.