Danner/Mags are good external pumps.
But they will warm the water if placed in the res. but can be used submersed.
Blue line are quality external pumps. They can never be used in the res.
If you don't mind in the res then there are DC pumps that are very adjustable.
I like Jeboa DC pumps for in the res.
Unfortunately, they have a reputation of leaking in external applications.