Everyone is going to respond differently to different AI's but I find that across the board, adex seems to be consistently good for most men. I would start with that and see how you do. In my personal experience, I find with arom, I need to take much more than normal, and even then, I am still likely to have an estrogen related issue, if I miss a dose. Letro, on the other hand, is very strong and you need to be careful not to over do it. It doesn't take a lot of letro to wipe estrogen out. You don't want too little or too much. More so, you want to be able to strike a balance.
Dosing will depend on your cycle and your personal response. You may need more AI while using dbol, than when you come off of it. I would start at .5mg about 3 times a wk, with the cycle you outlined, and then adjust from there.