Very nice tank.
I used to have a 75g silver dollar planted tank, filtered with a FX6 and a AQ 110.
The best manner I came up for positioning intake and oulets is as in the pictures below -
- The dual ouput from the FX6 was placed on the rear right corner of the tank, in such a way that the flow from one outlet hit the right side wall at an angle, and circled around the front of the tank (right to left); the flow from the other outlet hit the rear wall at an angle, and circled around the back from right to left.
- The FX6 inlet was also on the rear right corner of the tank, together with the inlet of the outlet. However, with the flow directed in the manner described above, the flow from the outlets exited completely away from the inlet. The input from the AC110n was on the opposite corner of the tank (rear left), together with the heater, and the output was baffled with the standard cut-soda-bottle DIY (see photo), such that the outflow from it was mostly side-ways along the back of the tank (instead as front as in the manner you say you don't want).
I loved that arrangement and I had it for several years. My happiness was related to having very strong filtration (flow from either filter was NOT reduced and were kept at full blast). Instead of being reduced, flow was diverted in a manner that did not create too much turbulence or bubbles (even in a smallish tank), and allowed profuse plant growth. Also, the system produced a net accumulation of debris on the left side of the tank (along left side wall), which made easy to vacuum often. By having the FX6 outlets hit the walls first (side wall and rear wall, respectively), and then flow along the walls, the disturbance to plants was minimal.
That tank eventually graduated into a 6 footer (125g), and I currently use a spray-bar with the FX6, and run it with dual AQ 110's in another panted tank.
FX6 output on rear right corner-
The actual tank after plant growth below, also showing AC 110 inlet - (note minimal disturbance due to AC outlet running at full blast). All plants are real (and yes, those are silver dollars).
Soda-bottle gizmo (can be made wider or narrower, or more on one side or the other to achieve different flow patterns) -