Since Anadrol 50 is derived from DHT, it can’t actually convert to estrogen (via the aromatase enzyme), and it’s not a progestin or a compound with progestenic activity so the estrogenic (?) side effects produced by it are of a very mysterious nature. It has been speculated that perhaps it can stimulate the estrogen receptor without actually being converted to estrogen and that's about as plausible an explanation as I’ve heard.
Proviron is not mainly an AI. It is a DHT that will not convert to Estrogen and as such it may compete with aromatase, without producing any estrogen, and slow Testosterone aromatization. However, it’s primary usages are to lower SHBG and to “harden” or “dry out” during a cutting/prep phase.
I do not know what you mean by “exstane” or if maybe it is just a misspelling/typo of exemestane (aromasin).
Read up some more on each of the popular AI’s (Arimidex, Exemestane, and Letrozole), the popular SERMs (such as, but not limited to Tamoxifen/Nolva and Clomid), and Proviron.
Of course keep learning about any other compounds you plan to run (such as the Anadrol you mentioned, and Testosterone because you should NOT run Anadrol without a base of some testosterone).
Make sure you understand and can explain the difference between each, what each is good for, and how each works – after that, you should be able to put together an appropriate protocol.