That's a relatively small oral dose. I wouldn't start taking the ancillaries unless it's warranted, unless of course you have pre-existing gyno and then I would use a LOW dose of anastrazole from the jump. A low starting dose such as 0.25mg 3x per week is a soft starting point. As always, adjust up as required. Having a SERM (Nolva/Ralox) on-hand is a must when cycling aromatizing compounds, especially if gyno-prone.
If you choose to stack with another compound, that could change your AI dosage. Having said that, both of the other two steroids you mentioned do not aromatize and should not increase the need for more aromatase inhibition.
I used Inhibit-P for prolactin control while cycling with 50-100mg of Trest ace. I'm sure I would have been fine without it but it was a cheap and mild addition to the cycle. I doubt you will have a need for a dopamine receptor agonist with only 20mg of Trest ace.