Sometimes a cycle will stall for reasons that are not immediately apparent. Your temperature, pH, filter and flow seem to be correct.
I've been checking around and it seems the temperature preferred by nitrifying bacteria is around 82*. No big deal, as far as I can tell, between 82* and 85*.
If your cycle has given nitrite and even nitrate readings, then you have some bacteria in your tank. Keep the aeration up as much as you can (filter on high). Don't touch your filter media.
Stir up the gravel a little to get the beasties active trying to find a place to grow. Then...
..next day, do a >50% water change.
If you think you'd like to try a cycle helper (bacteria in a bottle), I can recommend: Dr Tim's One-and-Only, Tetra Safestart, Nite Out or TLC Smartstart are some that I've heard good things about. These contain the actual bacteria that process the nitrogen cycle.
Because they are alive, they are date dependent and should be refrigerated. If you order the product from Dr Tim's website, it is shipped in an insulated container. By the way, Dr Tim Hovanec got his doctorate researching nitrifying bacteria. His original product (Bio-Spira) became Tetra Safestart.
Nutrafin Cycle and Seachem Stability, among others, do not have these bacteria. They have a different kind. If you want to get sciencey, I'll send you some URLs.