500mg is a good dose to go with. However I just have a personal differing opinion. (Please note the word opinion as my opinion is not fact)
I'm of the opinion that you can get away with a lower does on tour first cycle and still get great results. From my own research and personal doing I've realised I can get away with doing a 300mg per week cycle and still get good results. With my research I've noticed that lower than 500mg doses used to be fine way back and that 500mg only became a "standard" for people wanting to grow big quickly without going high doses and risking more sides. Now if you look at cycles all over (not just this great site) you'll notice that people rarely go higher than 500mg and that 90% of the time it's the max recommended dose for a cycle.
So if you look at it from a different point of view... we're actually subjecting ourselves to the max recommended on each cycle. Now this does not mean 500mg is wrong, it just means that 500mg is a safe dose without getting too many sides.
So I've personally done a 300mg cycle and for quite a few guys have recommended and helped them with running a 300mg cycle as a first cycle and they've seen great results. So my personal opinion is that we shouldn't jump in at the higher 500mg from the word go and should start slow as a means to get good results and test our reaction to a compound.
Imagine doing 300mg and getting good results. Then second time around being satisfied that we didn't have side's, now bump up to 500mg and get more impressive results because your now bigger body would require a tad bit more than 300mg to give you good results.
I feel it's similar to our eating habits. The more we grow, the more calories we need to maintain that size.
I feel it's the same with test, a 70kg person should not be using the same dose as a 90kg person as the heavier person would need more to maintain /grow. I am strongly of the opinion this is why some guys complain about getting sides on the same dose, it's mainly because the 70kg brother in law was trying to use the same dose as I do at 90kg.
Once again, this is my personal opinion and not anything proven or tested. Just based on my own experience. You don't have to follow it but I always think people should think about these things when doing a cycle or even taking any type of compound into their bodies.
As for your cycle. If you do go with 500mg, you're also set for a super cycle bud. Ensure your training and eating is dialled in and you won't go wrong.
Ai side I personally prefer aromasin as there is no rebound with it.