Welcome to AA!
I'm not sure that a HOB
Refugium is going to work very well on a 10g tank. You could always drill the 10g and plumb a refugium in below the tank.
People have converted HOB
power filters into mini-fuges but I'm not sure if there is a lot of benefit there. With enough LR
and frequent PWCs (at least once a week) you can have a very successful 10g tank.