Doyll has a good list of items for Optimal Cooling on
this thread.
The only item in your setup that may hinder airflow is the back intake fan. This is typically set up to exhaust air out the back to create a situation in which cool air flows into the case in the front and out the back without much interference. Having the back fan and front fans as intake may create odd flow patterns in the middle of the case, similar to mini tornados. But since that fan is easily switchable, give it a try. The bottom fans will help bring in the coolest air for any GPU's or PCI hardware.
Take a look at JayzTwoCents on YouTube for testing airflow patterns using the
smoke from incense sticks. It's a quick way to see how the air is flowing.