there is likely no need to run an AI with 4-DHEA, but do not make the mistake of believing Epistane acts as an AI. Epistane does not convert to estrogen, but it also does not convert to DHT...despite it being 5a reduced. epiandro or androsterone, on the other hand, will convert to DHT and have a high affinity to the ER, blocking estrogen at the receptor site.
Additionally, 4-DHEA will also convert to DHT, thus part of it's benefit.
So, if you want to dry things out a little and enjoy some added benefits, I would add in some epiandro or androsterone to the mix, without worrying about an AI.
My recommendation on that front would be either Androhard by Muscle Gelz or Alpha Andro by Alpha Gainz. Alpha Gainz is considerably cheaper and I like the carrier used, but there are many users who really like Androhard. If you run androsterone in transdermal, I would recommend you start at 200mg/day