Once you can answer this question OP, your choice will be a lot more clear. (Your question regarding July vs August mcat)
If you are scoring confidently closer towards July, then there's no reason to bump towards August. If you are iffy by then and have good study habits that could lead you to believe you can make a significant score increase in a month, then by all means take the August test.
With your current credentials, along with a decent mcat, you should be safe for applying in either August or September.
The way I look at it is I will always take the extra month of studying and a slightly later app if and only if I know i will dedicate that time towards studying and seriously improving my chances of a good score. You never want to take the test and feel as though you didn't prepare as well as you could have.
Best of luck!!
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