Lots of options on your flow/returns question. I have run 2 return pumps in one sump to different tanks, but now I have a manifold running one pump to 2 tanks with a total of 5 returns.
Some pros and cons
Cons with 1 pump, pros for 2
You will lose flow for any T's, elbows, bends, etc. so bigger pump required
You will probably want ball valves on the outlets after you T from a single pump because flow may be difficult to normalize
Redundancy limited and extra pump backup expensive to have around
Cons with 2 pumps, pros for 1
Probably costs more
Uses valuable sump space
More maintenance
Since pumps are awesome, but I also kind of like the lifeguard pumps as they are pretty quiet too and pretty cheap if you were looking for something with higher flow.
I have Jebao D.C. Pumps which are cheap and quiet, but I haven't had them long enough to report on quality.