First, I am not a woman. Second, I now have experience with my wife and can speak first hand about women and AAS. I bow to the expertise of someone like WPCHickD as she is clearly a pro. You are in the same position my wife was in.
Anavar seems to be the most used AAS for women in general. Anavar (oxandrolone) or "Var" is an oral AAS and is quite mild on your liver. Its probably the mildest oral steroid available today. The negative effects (very mild) that var has on blood work is an increase in cholesterol and a decrease in HDL. Dosages of up to 50mgs/day are easily tolerated by most women. Cycles can run from 6-12 weeks or even longer. Eight weeks is the absolute minimum. You can take liver support of course like TDC (not proven to be effective) but var is very liver mild. I never knew this but it was developed for women and children with AIDS and other muscle wasting diseases. The negative effects that var has on blood work is an increase in cholesterol and a decrease in HDL - I have yet to see a negative effect on liver enzymes from my wife.
If you are going to cycle Var, you will need to take taurine, potassium and magnesium, otherwise you will get muscle pumps (cramps) to an insane level, insane. 2 grams of taurine, 200mg of magnesium, and 200mg of potassium per day is the magic number for my wife.
With anavar you can diet as hard. You can eat below maintenance and do as much cardio work as you want and you will still put on some muscle while dropping fat.
My Wife's Current Cycle:
Week 1-2 20 Mg per day (around day 14-16 muscle pump will start up)
Weeks 3-6 30 Mg per day.
Weeks 6-12 depends on labs but up to 50 Mg per day.
She will take CEL CycleAssist for liver function ( can't hurt) and Fish Oil (important)
Keep your Macros good, high protein, moderate carbs, moderate fat.
On 20mg+ you will probably lose your period you may get cycle acne (my wife lost her but no acne). You will have increased libido and clit sensitivity (yep).
You need to have a solution to deal with an acne, If it occurs.
Your anti-estrogen question is odd to me. Women NEED estrogen. Leave your estrogen alone unless it is already running high (labs tell all). For my wife, high would be above 120. Estrogen is an issue for MEN. Typically lack of estrogen (older women an postmenopausal) is only an issue with older age.
I recommend you do a significant amount of reading BEFORE you start down this road and ONLY start any AAS AFTER you have your diet is in check (truly in check) and have been working out for an extended period of time. Getting a benefit from any AAS required discipline and HARD WORK. Do not be casual about this stuff.
Hope this helps and I am sure WPChickD can fix what I have wrong. This is information I have learned from reading AND from helping my wife.
FINALLY, you MUST run labs. It is critical to monitor liver values. A Comprehensive Metabolic Panel should be what you need (standard term) every 6 weeks (our regimen)