Albie
If it's possible to get a high hose loop close by, then that's the best because backflow is minimal (no check valve.) I don't have
that possibility, so I use a check valve BUT NOT an inline one on the manual pump -- VERY simple and is a Beckson foot valve on the end of my hose. From Defender, I believe.

I wouldn't recommend a CV on the electric pump (but admit that I have one and had no problems whatsoever.)

You can't go wrong with Shields MultiFlex bilge hose, which makes bends easily and is smooth bore and relatively inexpensive.
I would think about using 1-1/2 hose for both and reducing where necessary. Decrease the velocity head loss in hose and pipe whenever you can.
ken