WOW! I just read the ************ writeup on the Flowwolf. It looks like the Closed Loop just made it to the modern era (random flow, computer control, etc.).
One thing I'd suggest you think about is whether you really want the return pump/s to be so strong. That will mean a very high sump turnover rate, which can lead to difficult microbubbles. Like RK64 mentioned, if you instead do a true C/L (with the C/L drains on the back of the tank), you'll have less head loss. That would also keep you from having to deal with the super-high sump turnover rate.
THank you. That is definitely fuel for thought. The high sump turnover is a consideration. If I didn't like the closed loop I could always plumb it back into my sump. I will have to think it through. As for old school vs new school, sometimes a blend of both make better schools.